US2137503A - Switching apparatus - Google Patents

Description

1938- H. F. OBERGFELL SWITCHING-APPARATUS 2 Sheets-Sheet 2 Filed Dec. 28, 1937 FI S HERBERT F. OBERGF'ELL INVENT R BYAsmb ATTORNEYS.

Patented Nov. 22, 1938 UNITED STATES PATENT OFFICE SWITCHING APPARATUS Application December 28, 1937, Serial No. 182,136

4 Claims.

The present invention relates to switching apparatus and more particularly to improvements in switching apparatus suitable for use in automatic telephone exchanges.

As pointed out in the co-pending application, Serial No. 142,966 of Clarence E. Lomax and John H. Voss, filed May 1'7, 1937, one of the major items of cost, as regards the construction and installation of any automatic telephone exchange, is that of constructing the multiples extending between the bank contacts of the various auto matic switches. In accordance with conventional practice, this construction work is performed manually,.each multiple conductor being soldered at several corresponding contacts, respectively in- 'cluded in the switches of a particular group. By employing the improved arrangements disclosed in the above-mentioned co-pending application, the construction and installation costs are ma- 2o terlally reduced through the expedient of using uninsulated conductors which serve both as multiple conductors between a plurality of switches and as wiper contacts for the wipers of the individual switches. In this improved arrangement the lines incoming to each switch are terminated at common bus bar connecting elements with which the wipers of the switch are adapted to engage during the rotation thereof into contact with selected sets of the bank conductors. This necessarily means that each conductor connection through the switch involves two sets of series connected contact points, thereby increasing the possibility of trouble due to faulty contact conditions.

It is an object of the present invention to provide improved switching apparatus of the general form briefly described above, which is of simple and economical construction, and wherein series connected sets of contacts within the switch structure are entirely eliminated.

The improved apparatus as described in de-- tail hereinafter, is illustrated as including a plurality of substantially parallel spaced bank conductors, all positioned in substantially the same plane and adapted to serve both as multiple conductors and as bank contacts for a plurality of multi-contact relays. To this end, a plurality of wipers arranged in sets with the wipers of each set positioned on a line extending transversely with respect to the bank conductors, are provided. Each of the wipers includes a wiper end oppositely disposed with respect to one of the bank conductors and a flexible resilient shank portion which is fixedly mounted at a point remote from its wiper end. Each set of wipers forms a part of one of the multi-contact relays, which relays further comprise means for simultaneously flexing the shank portions of the associated wipers to move the respective wiper ends thereof into engagement with their respective oppositely disposed bank conductors. More specifically, a bar of insulating material is associated with each wiper set to engage the wipers of the associated set at points adjacent the respective wiper ends thereof and a toggle mechanism, comprising four arms, one of which includes the armature piece for an operating magnet, is provided for translating the bar, thereby, to ilex the shank portions of the associated wipers and to move the respective wiper ends thereof into engagement with their respective oppositely disposed bank conductors. In order to minimize the space requirements of a switching unit of any given size, alternate ones of the multi-contact relays are disposed on opposite sides of the plane formed by the bank conductors, whereby the length of these conductors is utilized to the fullest extent.

The novel features believed to be characteristic of the invention are set forth with particularity in the appended claims. The invention, both as to its organization and method of operation, together with further objects and advantages thereof, will best be understood by reference to the specification taken in connection with the accompanying drawings in which Figure 1 is a front view partially in section, illustrating one frame of a switching unit constructed and arranged in accordance with the present invention; Fig. 2 is a cross-sectional plan view of the apparatus illustrated in Fig. 1; Fig. 3 is a side view partially in section, illustrating the mode of mounting the relays with respect to the bank conductor field; and Figs. 4 and 5 are detail views illustrating the construction of one of the wipers.

Referring now to Figs. 1, 2 and 8 of the drawings, there is illustrated one frame or section of the improved switching apparatus as comprising a plurality of substantially parallel, bare bank conductors Hi, all positioned in substantially the same vertical plane, a plurality of wipers arranged in sets, three of which are indicated generally at I2, I 3 and i4, and means comprising a plurality of wiper switching mechanisms or relay structures l5, l6, l1, 18, etc, individually associated with the wiper sets for actuating the wipers of the respective associ-.

ated sets. The bank conductors ID are arranged in evenly spaced apart relation, and are supported on insulating members I 3, 23, etc. which extend between and are secured to oppositely disposed channel-shaped frame members 2| and 22. More particularly, the conductor field is preferably formed by slotting the insulating members i9, 20, etc. at correctly spaced intervals, following which the conductors are forced into the slots so that the sides of each slot tightly grip the accommodated conductor. In order to complete the assembly, each insulating member has overlying its slotted surface a second insulating member which is held in position by a U-shaped clamping bar. Thus, the bank conductors ID are clamped between the insulating member I9 and a cooperating insulating member 23 by means comprising screws 24 and 25 which extend, respectively, through openings provided in the respective side portions of the oppositely disposed frame members 2i and 22, through openings drilled in the respective ends of the members I9 and 23, and are threaded into tapped drill holes appropriately disposed along a channel-shaped clamping member 25 which is coextensive with the insulating member 23. Each of the other supporting assemblies is identical with that just described.

As best shown in Figs. 4 and 5, each of the wipers is provided with a wiper end 21, a flexible resilient shank portion 28, and a terminal end 29. These wipers are preferably stamped from flexible resilient material, such for example, as brass or bronze. The wiper end of each wiper is formed by bending over the two halves of a spiit enlarged portion of the stamping so that a slot 9 is provided which is of slightly less width than the diameter of the bank conductors. As thus constructed, the internal faces of the bent over portions engage opposite sides of the associated bank conductor to form a two point contact therewith when the shank portion of the wiper is flexed to move the wiper end into engagement with its associated bank conductor.

The mounting assemblies for the wipers of the various wiper sets are so arranged that each wiper is insulated from each of the other wipers. Since the respective assemblies for the various sets are identical, only that for mounting the wipers of the set l2 need be considered in detail. In brief, this assembly comprises a pair of flat insulating strips 30 and 3| between which the shank portions of the wipers are clamped at points remote from the respective wiper ends of the wipers. The strips 30 and 3i are clamped together with the shank portions of the wipers therebetween by means comprising a U-shaped member 32, a frame member 33, and stud screws 34 extending through openings in the members 32, 30 and 3| and threaded into tapped drill holes provided in the frame member 33. This frame member is mounted on the end frame members 2| and 22, by two bolts 35 and 35 extending through openings drilled in the side portions of the oppositely disposed end frame members 2| and 22.

Due to the structure identity between the wiper actuating mechanisms l5, l6, l1, l3, etc., only that indicated generally at I need be considered in detail. This mechanism, namely the mechanism I5, is mounted upon a bracket comprising outwardly bent portions or bracket pieces 31 and 38 formed integral with and extending horizontally from the frame member 33. In brief, the mechanism comprises an operating magnet 39 supported between end brackets 40 and 4i secured to the bracket pieces 31 and 33 by screws 42 and 43, and an armature piece 44 forming one arm of a pair of toggle linkages for actuating the wipers of the set l2. These toggle linkages are located at the respective ends of the magnet 39, that at the right end of the magnet as shown in Fig. 3 comprising, in addition to the armature piece 44, three additional arms 43, 43 and 41, the last-mentioned of which is fixedly mounted on the bracket portion 31 of the frame member 33 by means of screws 43. The toggle linkage is interconnected by suitable pivot studs 49, 50, SI and 52, the two last-mentioned studs forming the respective pivot points for the arm 44 and the armature piece 44. Normally, the armature piece is restrained to engage two stop members 53 and 54, respectively mounted on the end brackets 40 and 4| by screws 55 and 53, respectively, through the provision of a coil spring 41 interconnecting the lower end of the armature piece 44 and a finger extending from the toggle linkage arm 41.

Since the second toggle linkage, namely, that provided at the left end of the operating magnet 39, as shown in Fig. 1, is identical with that just described, no further discussion is deemed necessary to an understanding of the operation thereof.

In order to actuate the wipers making up the wiper set i2 by means of the two toggle linkages just described, there is provided a cross member 53 interconnecting the two linkages and having mounted thereon, by means of screws 53 and 69, a bar of insulating material which is suitably slotted along its free edge to accommodate the bent over halves of the wiper ends of the respective wipers. Preferably, the wiper ends are of such size that they are freely movable in the iespective accommodating slots provided in the bar of insulating material 6|.

The magnet 39 is energized through circuit connections, not shown, interconnecting the two ends of its winding with the terminal connectors 62 and 63, which are adapted to be connected to the control apparatus associated with the mechanism ii. In this connection is should possibly be mentioned that the frame member 33 including the bracketportion 31 thereof is constructed of a non-magnetic material such as bronze or brass, whereby the magnetic circuit of the operating magnet 39 is not short-circuited. This magnetic circuit comprises, in addition to the usual core for the magnet, the end brackets 43 and 4! and the armature piece 44 extending therebetween, all of these elements being constructed of a material such, for example, as iron, having good magnetic properties.

As pointed out above, normally the two toggle linkages embodied in the wiper actuating mechanism II are maintained in their cocked positions through the bias exerted on the armature piece 44 by the coil spring 31. When, however, the magnet 39 is energized, it attracts its associated armature piece 44, thereby to pivot this piece in a clockwise direction and to break the two toggle linkages. Due to this operation, the two pivot studs 43 and ii are moved toward each other and the pivoted stud 50 is moved in a clockwise direction. As a result. the bar of insulating material 3| is translated to the right, thereby to flex the shank portions of the wipers embodied in the wiper set I2 and to move the respective wiper ends of these wipers into engagement with their respective oppositely disposed bank conductors. As a consequence, the lines terminating at the bank conductors it are connected by way of the wiper springs to the lines terminating at the terminal ends of the wipers. Following the deenergizaticn of the magnet 39, the toggle linkages are returned to normal through the bias exerted on the armature piece 44 by the coil spring 51 and the supplemental bias exerted on the two linkages due to the resiliency of the wiper springs embodied in the wiper set l2.

Assuming that the size of the bank conductor' fleld is such that ten three-conductor lines are terminated thereat, this group of lines is selected upon energization of the magnet 39. In accordance with well-understood telephone practice, further selection of a particular line in this group may be attained by terminating the terminal ends of the wipers in the set I 2 in the contact springs of a group of line selecting relays arranged in conventional manner.

As pointed out in the introductory portion of the specification, the size of a frame or section of a given line capacity is minimized by positioning alternate sets of the wipers on opposite sides of the plane occupied by the bank conductors. This arrangement is best illustrated in Fig. 3 wherein the wiper set l3 and the actuating mechanism associated therewith are mounted on the right side of the vertical plane formed by the conductors l0, and the sets l2 and H, together with the actuating mechanisms l5 and I1 respectively associated therewith, are mounted on the left side of this plane. By this arrangement, the active length of the bank conductors may be utilized to the greatest extent.

While there has been described what is at present considered to be the preferred embodiment of the invention, it will be understood that various modifications may be made in the structure thereof, and it is contemplated in the appended claims to cover all such modifications as fall within the true spirit and scope of the invention.

I claim:

1, Switching apparatus comprising, in combination, a plurality of substantially parallel spaced bank conductors all positioned in substantially the same plane, a set of wipers positioned on a line extending transversely with respect to said conductors, each of said wipers including a wiper end oppositely disposed with respect to one of said bank conductors and a flexible resilient shank portion, means fixedly mounting the shank portions of said wipers at points remote from their respective wiper ends, an operating magnet, an armature piece for said magnet, and means including a toggle mechanism controlled by said armature piece for simultaneously flexing the shank portions of said wipers to move the respective wiper ends thereof into engagement with their respective oppositely disposed bank conductors.

2. Switching apparatus comprising, in combination, a plurality of substantially parallel spaced bank conductors all positioned in substantially the same plane, a set of wipers positioned on a line extending transversely with respect to said conductors, each of said wipers including a wiper end oppositely disposed with respect to one of said bank conductors and a flexible resilient shank portion, means flxedly mounting the shank portions of said wipers at points remote from their respective wiper ends, an operating magnet, an armature piece for said magnet, a bar of insulating material associated with said wipers, said bar engaging said wipers at points adjacent the respective wiper ends thereof, and means including a toggle mechanism controlled by said armature piece for translating said bar thereby to flex the shank portions of said wipers and move the respective wiper ends thereof into engagement with their respective oppositely disposed bank conductors.

3. Switching apparatus comprising, in combination, a plurality of substantially parallel spaced bank conductors all positioned in substantially the same plane, a set of wipers positioned on a line extending transversely with respect to said conductors, each of said wipers including a wiper end oppositely disposed with respect to one of said bank conductors and a flexible resilient shank portion, means fixedly mounting the shank portions of said wipers at points remote from their respective wiper ends, an operating magnet, an armature piece for said magnet, a toggle mechanism including four arms one of which comprises said armature piece, and means including said toggle mechanism for simultaneously flexing the shank portion of said wipers to move the respective wiper ends thereof into engagement with their respective oppositely disposed bank conductors.

4. Switching apparatus comprising, in combination, a plurality of substantially parallel spaced bank conductors all positioned in substantially the same plane, a set of wipers positioned on a line extending transversely with respect to said conductors, each of said wipers including a wiper end oppositely disposed with respect to one of said bank conductors and a flexible resilient shank portion, means fixedly mounting the shank portions of said wipers at points remote from their respective wiper ends, an operating magnet, an armature piece for said magnet, a bar of insulating material associated with said wipers, said bar engaging said wipers at points adjacent the respective wiper ends thereof, a toggle mechanism including four arms one of which comprises said armature piece, and means including said toggle mechanism for translating said bar, thereby to flex the shank portions of said wipers and move the respective wiper ends thereof into engagement with their respective oppositely disposed bank conductors.

HERBERT F. OBERGF'ELL.

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