US2575052A - Multiple selective switch - Google Patents

Description

NOV. 13, 195.1 H, R FOLTZER 2,575,052

MULTIPLE SELECTIVE SWITCH Filed Aug. 19, 1949 Patented Nov. 13, 1951 MULTIPLE SELECTIVE SWITCH Henry R. Foltzer, Caracas, Venezuela Application August 19, 1949, Serial No. 111,151 In Cuba July 5, 1949 2 Claims.

This invention relates to multiple selective switches of the kind employing as selecting elements metallic perforated or otherwise partially insulated stencils made of thin sheet metal.

One of the objects of the invention is to improve known switches of this kind permitting the use of plane metallic stencils consisting of a metallic sheet having apertures which correspond to contacts in circuits which are not to be energized. Although the stencils may be made of thin sheet metal, they will not overheat even though they are employed to close circuits through which large currents pass, as they are carried by a thick metallic perforated plate connected to the common return wire of all the circuits.

The improvements forming the object of the invention consist in providing a selective switch controlled by means of a conductive sheet stencil and in which means are provided to open all the diierent circuits at the same time,` so as to subdivide the total intensity of the current which is being shorted, thus avoiding or reducing to a minimum the arcing or sparking during circuit breaking.

Another object of the invention is to provide a selective switch of the kind above referred to which requires but small pressure for energizing a large number of -contacts and in which rigid springless fixed contacts are provided which, when the switch is in idle position, do not project above the metallic stencil-carrying-plate; while, when the stencil is in operating position, they project slightly through the perforationsv of said plate, whereby the stencil carried by said plate is pressed in a known manner by a flexible insulating pad backed by a rigid pressure plate rst against the thick metallic perforated stencil-carrying plate and then against the "working contacts, viz. those of the conta-cts, which project out of the perforations of said stencil-carrying plate, in correspondence of unperforated parts of the metallic stencil, while the other contacts project through the metallic stencil. The contacts which engage the stencil are pressed by said pad which also presses the unperforated portions of the stencil against the plates, thus establishing a good conductive ccnnection with said plate.

Another object is to provide a selective switch of the kind above referred to, in which the contact-carrying plate may be made in sections adapted to be connected together, thus rendering it possible to construct switches having a large number of contacts by connecting together 2 standard units each having a, relatively small number of contacts.

Other objects and advantages of the invention will beapparent from the following descrip-f tion made with reference to the attached drawing, in which:

Figure l is an elevation with parts in section, showing a selective switch according to the invention with a stencil inserted in place, the switch being in open or circuit-breaking position.

Figure 2 shows diagrammatically and somewhat enlarged a part of the same switch in circuit-closing position.

Figure 3 shows, nfor the purpose of illustration only, a wiring diagram having nine independent circuits adapted to be selectively controlled by a small-S-contact switch.

Figure 4 shows a small stencil adapted for use with a selective switch such as shown in Figure 3.

In the embodiment shown in Figure 1, the selective switch consists of an insulating plate I tted to a metallic frame 2 in which plate I has a number of -contacts 3 embedded at regular intervals. The contacts comprise a body 3, va tail end 4 to which the wires leading to the circuits 5 to be energized are connected and a projecting head 3', preferably of reduced cross-section. The circuits 5 are connected in parallel with a common lead connected to one of the terminals 6, while the other terminal is connected through another common lead to a perforated conductive plate 'l having a thickness somewhat less than the height of contact heads 3 and a number of perforations that is equal to the number of said projecting contact heads 3', but of greater diameter than the latter, which thus may freely pass therethrough without touching the perforation wails.

Plate 1 is slidably mounted on uprights or bolts 9 provided with stop heads and is pushed away from insulating plate I by coil springs 8 encircling said bolts. Above plate l a pressure plate I0 is provided slidably mounted on columns II and carrying at its lower side, facing plate 1, a pad I2 made of rubber, felt or other yielding material. On columns II springs I4 are tted between pressure plate I] and base frame 2, so as to keep plate I0 away from plate 1, when it is in idle or open position, viz. when it is not positively pressed against the spring 8 by means to be described below. In the idle position of plate IU, in the gap between plate I0 and plate 'I a conductive sheet I3 may be inserted, which may be perforated at desired portions, thus acting as selective switching means.

Plate I may be pressed towards plate I against the pressure of springs III by any suitable pressure means. In the embodiment shown, said pressure means consists of a cam disk I preferably shaped as an Archimedean spiral and rotatably mounted on a shaft mounted on a cross bar I8, on vwhich, shaft also a disk 2I, provided with a trapezoidal notch 24, and a control handwheel 2B are mounted. Bar I8 carries in correspondence with disk 2| a stop finger 22 slidably mounted within a cylinder and pressed outwardly by a spring 22. A push rod I1 bearing with its lower end against plate In'is-slidably.

The operation of the selective switch is as follows:

When the switch is in inoperative position, with the parts as shown in Figure l, the stencil constituted'by a thin perforatedv metal sheet I3, like that shown in `Figure 4, is `inserted in the gap between plate 'I' and pad I2. By rotatingcam I5 until the high part thereof comes into contact with roller I, the rod.. I'I will press plate I0 and pad I2 against stencil I3, which thus presses plate 'I' towards plate I, until contact heads 3 project slightly above plate 'I and are pressed either against. the unperforated parts of stencil I3, or. through the .perforations of the stencil, against pad I2, as shown in Figure 2. D ue to the. fact that stencil` I3.is made. of thin sheet metal (generallyaluminium or copper of a thickness of the order of 2-3 tenths of millimeter), it is slightly bent at the,- point ofcontact'with a head 3' (as the head of vcontact IE5 indicated in Figure 2). Whileatthe points Where vthe heads 3 are aligned with the perforations (as is the case with the contacts. 2l, Fig. 2), these pass through the perforations. The unperforated parts of the stencil sheet I3 whichare not in the immediate proximity of. contact heads 3 thatare pressed-against the stencil plate (as contact 26, Fig. 2), are pressed .against the perforated plate l which, being of substantial thickness, easily conductsl very large currents, while the stencil acts as independent conductor only for very narrow vcircular areas about the active contacts 26, Fig. 2. Thus heating of the' thin stencilsheet, is .minimized even whenV large currents .pass through the contacts.

Fig. 3 shows how by inserting on plate. 'Lof a nine-contact switch a stencil like that shown in Figure 4, contact points 3G and 3l of the stencil willenergize lamp . groups 28, 29, contact point 33 will energizecoil andcontact point 3,5 will energize motor 34. The otherdevices as shown in Figure 3 will Aremain de-energized, as Atheir contacts .are aligned with the perforations of stencil I 3, Fig. 4. As shown in Figure 4, the stencils are usually provided with a tab bearing useful indications, as indicated at 31.

When the circuits are to be de-energized or thestencil changed, handwheel 29 is rotated until roller I 5 rolls off of high part 25 of cam I5 and then, by the action of springs I4 it snaps into the dwellv of cam I5, thus permitting plate Il) with pad I2 and stencil-carrying plate 'I to snap yinto the position as shown in Figure 1 .by the action of springs I@ and 8. As this snapping action is practically instantaneous, al1 contacts are instantaneously brought out of contact with the stencil, thus minimizing arching or sparking. Furthermore by this device changing of' the stencils is rendered possible with the device connected to the current supply line.

In order to judge when the switch is in its full closing position, viz. with the plate I Il in its lowermost position, the slidable nger 22 pressed by a spring 23 fitted in a thimble is fastened to cross bar I8 in such a position as to snap into notch 2li `of disk fZI when the switch is in full closing position. The position of bar I8 on columns II, may be registered by means of nuts I9.

From the foregoing the advantages of the improved switch are apparent. It may be mentioned however that, due to the construction and mounting of plate I, this may be made in sections, preferably ofv plastic material, having embedded therein a number of rigid contact wire sections, for instance pieces of copper wire having a diameter of about;2 millimeters. The plate sections will be--usually provided with maleqand female parts at their borders for ensuring.Y registering andl locking of the plate sections In this manner very large switches, designed for selectively switching many hundreds or thousands of circuits (as it is the'case for large lamp panels for advertising purposes) may be made economically by employing standard units containing a limited `number of contacts. The sections of contacts-carrying plate I may rest upon a perforated insulating board fitted to frame 2 andmay be held together .by any desired means.

It is also apparent that the inventioumay undergo lnumerous ,changes within the. scope of the claims. Thus the contacts.3, 3', 4 need .not be shaped as shown, but may be made of wire of any suitable section,.and,may be of the same diameter from end to end; the pressure means may be ofany suitablekind, such as pressure screw, pneumatic or hydraulic pressure means;

plate I may be slidably mounted on stems iitted under plate I@ and provided with abutment heads or the like; in which case the springs .8 may be less powerful thaninthe case as shown,.or even may be eliminated.

I claim:

1. A multiple selective .switch comprising an electrically non-conductive base plate, Va plurality of contacts` fixed in said plate, an apertured conductive plate mounted for movement parallelly towardsv and away from said base plate and having the apertures located so as to encircle elongated portions of said contacts without engaging same, a pressure plate rmounted for movement parallelly to said apertured conductive plate and yieldably urged away from said conductive plate, a yieldable pad fitted to a face of the pressure plate and being adapted to press said apertured conductive plate towards thebase plate so as to cause-the elongated portions of said contacts to traverse the ythickness of the conductive plate and to project slightly therethrough, a selectively aperturedstencil made of al sheet of-conductive material and adapted to be inserted between' said conductive plate and said pad when the pressure plate -is in retracted position, means for pressing said pressure plate and pad against said apertured conductive plate, means for conductively connecting individual leads to each of said contacts and, through the devices tofbe energized, to one of the terminals ofY the sourcerof. current, means for connecting asingle return lead to said apertured conductive plate and tothe other terminal of the source of current; andspring meansmaintaining the con- 5 ductive plate at a. position wherein the surface of such conductive plate adjacent the yieldable pad is further removed from the base plate than are the ends of the elongated portions of the contact members.

2. A multiple switch according to claim 1 in which the yielding pad is tted under the pressure plate and the conductive apertured plate is slidably mounted on guide stems provided with stop heads tted in said base plate, and compression springs are tted on said guide stems between said base plate and said conductive plate.

HENRY R. FOLTZER.

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

UNITED STATES PATENTS Number Name Date 1,627,993 Pedersen May 10, 192,7

2,006,436 Bowers July 2, 1935 2,137,131 Cheli Nov. 15, 1938 2,471,902 Rue May 31, 1949 FOREIGN PATENTS Number Country Date 937,179 France Mar. 1, 1948

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