US2350442A - Substation protector - Google Patents

Description

June 6, 1944; 5 KER SUB-STATION PROTECTOR Filed April 18, 1942 2 Sheets-Sheet l m A 6 Q 11,

Q a A J 1 w j 79 June 6, 1944. BAKER 2,350,442

SUB-STATION PROTECTOR 2 Sheets-Shet 2 Filed April 18, 1942 4 7 I I H.136,

mm J. 7 A 79 WW Patented June 6, 1944 $UBSTATION PROTECTOR John S. Baker, Chicago, Ill., assignor to Cook Electric Company, Chicago, I lL, a. corporation of Illinois Application April 18, 1942, Serial No. 433,521

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This invention relates tc terminal boxes and more particularly to sub-station protectors used particularly for telephone, telegraph and like systems.

Terminal boxes of the type herein disclosed are used in communication systems and furnish sub-station protection for the subscribers drops and instruments. These terminal boxes are generally provided with protective devices and associated terminals or contact members for connection with the line wires and the subscribers leads. 'In United States Letters Patent No. 1,800,978, granted to me on April 14, 1931, and assigned to the assignee of this application, a terminal box of this type is disclosed which comprises a compact, durable and simple construction. It discloses, however, a mounting in the form of a porcelain base that is designed to carry the protective devices and associated terminals in a manner particularly for the device in question. Consequently, the remaining portion ofthe device is constructed to receive this porcelain base. The device does not permit the employment of a protector unit of a character that may be interchangeably used in other devices of the system. It was, therefore, impossible to effect standardization of equipment and its attendant economies in purchasing, inventory and-maintenance.

' Broadl an object of the invention resides in providing, in a communication system, a terminal box of the type and kind that permits of ready adaptation of a standard form of protector unit which may be interchangeably used in other unit divisions of the system whereby greater flexibility and efficiency in the use of the equipment and desirable economies in operation as the result of smaller inventory requirements will be obtained.

The invention is directed more specifically to an improved structure capable of embodying an improved standard form of protector unit in a terminal box of the type described whereby equipment flexibility and standardization in a communication system are secured and labor and inventory economies will be effected, which will provide for greater efliciency, better service and lower maintenance cost.

A further object of the invention is to provide an improved structure in a terminal box of the type described capable of employing a standard form of protector unit, which structure is simple, permits quick and rough handling without danger of breakage, provides insulating parts that have high insulating value and great tensile strength and therefore higher resistance to breakage from the shocks of severe eleotricalf'disf charges, and further provides greater physical strength and durability. The mounting bracket for the protector unit maybe made of metalan'd brittle porcelain parts maybe eliminated. Other objects and advantages of the invention will be apparent from the following detail de scription when taken in connection'with the accompanying drawings, which form a part hereof. In the drawingsi Figure 1 is a side elevation of a terminal box embodying the invention, the-box andthe cover being shown mountedin position upon a wall cke Fig. 2 is a view similar to Fig. 1 but with the cover shown in dotted lines; Fig. 3 is a front elevation of the terminal box with the cover shown in dotted lines-;' Fig. 4 is a perspective view of a novelform of bracket or mounting for the protector unit;

Fig. 5 is a vertical sectional viewtaken along line 55 of Fig. 2 of the protector unit; Fig. 6 is a transverse sectional view taken along line66 ofFig.3;

Fig. '7 is a top plan view with the cover removed to show one position of the terminal box upon the wall bracket;

Fig. 8 is a view similar to Fig. 7 but showing another position of the terminal box upon the wall bracket; Fig. 9 is a bottom view of the terminal box and the wall bracket to show the structure supporting the terminal box in itsposition shown in Fig. 7i and Fig. 10 is a similar viewto show the structure supporting the terminal box in its position shown in Fig. 8. A terminal box illustrated in the accompanying drawings may include a bracket I, one or more protector units {adapted to be detachably connected to bracket I, a cover 3 adapted to be placed over'the whole So as to enclose the same, and a wall mounting bracket 4 to which the base of bracket I may be attached.

Bracket l is preferably made of conducting material in the form oija cast or sheet metal stamping, while protector unit Zniay be a stand ard-unit capable of ready replacement and of interchangeable use in other .unit divisions of a communication system, the body thereof carrying the protective devices and associated terminals accommodating incoming and outgoing connections, being of a strong non-absorbent',.nonconducting resinous material. Bracket 1 includes a base 5 and a vertical wall 6 having a grounded terminal I formed by an ear 8 turned inwardly from vertical wall 6. A ground wire 8' is attached to terminal 1 and is led through an opening 9 provided therefor in base 5. Whether made as a casting or as a sheet metal stamping, bracket i may have inturned flanges l and I along opposite side edges. of vertical wall 6 to guide and support cover 3. Cover 3 is held in spring latching relation with base when the cover is in its position shown in Fig. 1 by reason or" a bead |2 formed about its lower edge that will snap over opposed side edges of this base 5.

A mounting plate l5 is'attached in position upon the face of vertical wall 6 so as to carry the protector unit in its proper position and relation with respect to vertical wall 6 and base 5.- One form of attachment that may be employed, although other forms may be used with equal advantage,- is a-flange l6 that may be welded or otherwise afiixed to the front face of vertical wall 6.; Plate I5 is preferably arranged to extend transversely from vertical wall 6 and is provided with means for securing and maintaining the protector unit in a predetermined position with respect to this plate and wall 6. The specific means disclosed herein is in the form of two flanges designated I! and I8. Flange I! is provided along the upper edge of plate |5 and acts as a bearing stop against which a'spring-formed ground terminal I9 on protector unit 2 presses in order to assure a perfect grounding contact between certain of the protective devices on the protector unit and this frame I which is permanently grounded through ground terminal l.

Flange I8 is disposed .along the lower edge of plate |5 and is provided With a cut-away portion 23 into which a shoulder 10 on the body of the protector unitZ seats. and 13,- means are provided for detachably connecting protector unit 2 to this plate I5. This means together with shoulder 13 serve also to center .or properly position the protector unit 2 Inaddition to flanges i1 upon plate l5 as well as make it possible to make 5 the protector unit of a design that will be readily replaceable or interchangeable with units of other equipment in the system. This means may comprisemetallic members 2| adapted, as shown indetailin-Fig. 16, to pass through aligned insulation sleeves 22 and 23 having their inner ends in overlapping relation and being seated in openings 24 in;plate l5. Irrespective of whether meitallic members 2| arefirst slipped through sleeves 22 or sleeves 23, one end of these members 2| is provided with a head 25, while the other end is :formed into a head 26 after these members are inserted in sleeves 22 and 23. Metallic members 21 are'internally threaded and receive bolts 28 that mount the protector unit 2 upon plate l5 and ;-bolts 29 at the opposite ends which form terminals for the incoming or line wires 29. -In order to carry out the feature of interchangeability, the construction of the protector unit herein disclosed need not be necessarily emblo'yed. ,The form of protector unit shown has been. disclosed and claimed in United States Let- :t'ers Patent No. 2,223,540, granted to applicant on December 3, 1940. ,It comprises molded resinous-material adapted .to carry fuses 3| between -cl'ipsi32 and 33. Fuse. clips 32 are attached at one end of base 30 by rods 34 extending longit'udinally through the base.

"o i-rods34 are threaded, as .indicated at 35. Lock n ut's 36 hold .rods 34in position upon base 30.

The opposite ends The usual terminal nuts 3! and the theaded ends tioned a predetermined distance from 35 form terminal posts 38. Fuse clips 33, together with clips 39 of lightning arresters 40, are attached to base 30 by metallic sleeves 4| which are provided with heads 42 at one end. The opposite lightning arrester clips 44 are also held by similar metallic sleeves 45 that are riveted over at one of their ends as at 46. Spring-formed ground terminal I9 is connected through these sleeves 45 with lightning arrester clips 44 to provide an earth connection for lightning arresters 40.

Base 30 may be molded with passages for receiving rods 34 and sleeves 4| and 45, or these latter parts may be molded directly in base 30 during the molding operation. Sleeves 4| are located in base 30 to form with bolts 28 and 29 the electrical connection for one side of the circuit, say, the incoming side to one end of each fuse 3|, the bolts 28 also serving as the fastening means for each protector unit 2 upon mounting plate I 5. Locating clips 32 and 33 in the manner shown allows the circuit to continue rearwardly of base 30 from the point of connection 4| through fuses 3|, then through rods ,34 from the rear .of the base to the top thereof at terminal posts 38, the term top being relative and depending how units 2 are arranged for mounting upon plate l5. Rods 34 and sleeves 4| are in different planes in base 30 so that electrical contact between these parts is prevented.

Sleeves 4| may be located anywhere intermediate the base 30. If fuses 3| are of the character herein shown, these sleeves 4| may be disposed substantially closer to the top end of base 30 so that fuses 3| extend in a general downwardly direction to make proper contact with rods 34 at clips 32. The circuit is then taken back through base 30 by means of these rods 34 which have their upper ends comprising the aforesaid terminal posts 38 adapted to receive the customers drop Wires or outgoing connections 50.

If high voltages are accidentally picked up through the side of the line connected to terminal .posts 38, lightning arresters 40 afford no protection to equipment connected therein, if the fuses should'blow, because the lightning arresters are on the side of the fuses opposite the side connected to terminal posts 38. If one or both of the fuse beginning with clip 33 and extending through the line connected to terminal posts 29.

Consequently, any high voltage that maybe induced by lightning or directly obtainable there from, or otherwise caused to exist upon the side of the line connected to terminal posts 38, is apt to remain for a time without being dissipated. It is undesirable to allow such high voltages to remain upon these parts or upon the sideof the line connected to terminal posts 38 without being immediately grounded, particularly when such voltage charges may reach 2500 volts or more. To protect equipment at both ends of the fuses against such high voltage charges, arrester blades 5| or the likeare provided upon the upper end of rods 34 near terminal posts 38. Arrester blades 5| may have saw-toothed edges 52 posilightnin arrester block 40 to form a permanent discharge gap whereby abnormal high voltage charges may be dissipated through the ground that is established by the carbon block of the arrester latter being connected to the spring-formed blade 19 that is adaptedtobe grounded by its engagement with flange I! of mounting plate Iii. Only the arrester blades are necessary as to material required to form this second arr ester. These blades 51 are carried upon rods 34 at terminal ends 38. No additional parts are required.

Although I have described only one form of protector unit disclosed in my aforesaid Patent No. 2,223,540, it will be understood that any form of protector unit may be used.

Wall bracket 4 for mounting the sub-station protector may comprise a vertical wall leg 60 and a slotted base leg 6|. The sub-station protector is adapted to be seated upon slotted'leg 5! with a plate 62 inserted therebetween. Plate 62 is limited in width so as not to interfere with openings 9 and 58 through which the ground wire 8 and the line Wires 29 and the subscribers wires 50 pass. Base leg 6| may be provided with a central slot 63 which is slight- 1y larger in width than the diameter of fastening screws t l. These screws are, therefore, free to move in and out of slot 63. The inside edges of the two parts of base 6| formed by this central slot 63 are provided with pairs of semicircular openings 65 and 66, each pair being adapted to receive the fastening screws 64 depending upon the position of the protector. If fastening screws 64 lie in openings 65, as illustrated in Fig. 10, the line of center of these fastening screws lies along the inside edge of the left-hand part of base 6|. If fastening screws 6 lie in openings '66, as illustrated in Fig. 9, the line of center of these fastening screws lies along be inside edge of the right-hand part of base iii. The position of the terminal box upon the wall bracket will depend upon the direction of approach of line wires and subscribers wire, and also will depend upon the position in which wall bracket 4 may be mounted.

From the foregoing description, it will be observed that the terminal box disclosed herein provides unique sub-station protection for subscribers drop and instrument wires and combines in this structure features that permit the use of a type of interchangeable protector unit forming a part of standardized equipment capable of use in other unit divisions of a communication system. The feature of interchangeability and standardization of equipment is particularly valuable for small and medium size exchanges used in factory and office systems, in unattended exchanges and in field communications.

The bracket l is a simple, inexpensive and durable mounting for the protector units. It serves to receive a standardized protector unit having a molded insulation body with protective devices and associated terminals so mounted that the ground for the protective devices may maintain a spring-pressed contact with bracket 1 in order to effect grounding through this bracket. Fragile ceramic bases and parts are thereby eliminated and insulating parts are substituted that have high insulating value and great tensile strength, and therefore, higher resistance to breakage from shocks of severe electrical discharges.

The simple form of attachment for the protector unit assuring centering or a predetermined positioning of the protector unit when being mounted and the fastening thereof in this position provides a ready means of standardizing the protector unit for interchangeable use or adaptation in other equipment of the system where prostructed units.

tector units are necessary. In other words, this simple form of attachment admits of the use of a standard protector unit for the entire system and reduces inventory costs. A small number of the units disclosed herein may be carried instead of a number of many differently con- The standard simple form of attachment also standardizes the mounting of these protector units so as to simplify the mounting and reduce the labor involved.

Without further elaboration, the foregoing will so fully explain the gist of my invention that others may, by applying current knowledge, readily adapt the same for use under varying conditions of service, without eliminating certain features, which may properly be said to constitute the essential items of novelty involved, which items are intended to be defined and secured to me by the following claims.

I claim:

1. A terminal box comprising a mounting bracket of conductor material having a base and a vertical wall, a conductor plate extending transversely from said vertical wall, a protector unit including protective devices and associated terminais accommodating the incoming and the outgoing conductor connections and a ground terminal in electrical relation with certain of said parts, means for detachably connecting said protector unit to said transversely extending plate, said ground terminal being in contact with said plate, and a cover placed over the whole so as to enclose the same.

2. A terminal structure of the type described comprising a mounting bracket of conductor material having a base and a vertical wall, a conductor plate extending transversely from said vertical wall, a protector unit including protective devices and associated terminals accommodating incoming and outgoing conductor connections and a ground terminal in electrical relation with certain of said parts, said ground terminal having a resiliently formed finger thereon, and means for detachably connecting said protector unit to said transversely extending plate, said resiliently formed finger having a spring-pressed engagement with said plate, the tension of spring-pressed engagement being maintained by said means connecting said protector unit upon said plate.

3. A terminal structure of the type described comprising a bracket of conductor material having a base and a vertical wall, a mounting plate also of conductor material extending outwardly of said vertical wall, a protector unit including protective devices and associated terminals accommodating incoming and outgoing conductor connections, a ground terminal on said protector unit, and means for mounting said protector unit in insulated relation upon said plate and with said ground terminal in electrical contact with said plate.

4. A terminal structure of the type described comprising a bracket of conductor material having a base and a vertical wall, a mounting plate also of conductor material extending outwardly of said vertical wall, a protector unit including protective devices and associated terminals accommodating incoming and outgoing conductor connections, a ground terminal on said protector unit, means for mounting said protector unit in insulated relation upon said plate and with said ground terminal in electrical contact therewith, a grounded terminal for said bracket, and a cover placed over the Whole so as to enclose, the same, said cover being grounded ,upon said bracket.

5. A terminal structure of the type described comprising a grounded metal bracket having a base and an upstanding wall, a metal mounting plate-extending outwardly of said wall, a protector unit including protective devices and associated terminals accommodating incoming and outgoing conductor connections, means for detachably connecting said protector unit in insulated relation upon said plate, and means for grounding certain of said protective devices .upon said plate and said bracket.

6. A terminal structure of the type described comprising a grounded metal bracket having a base and an outwardly extending Wall, a protector unit including protective devices and associated terminals accommodating incoming and outgoing conductor connections, means for detachably mounting said protector unit upon said wall in insulated but extended relation with respect thereto, and means for grounding certain of said protective devices upon said wall through said mounting means.

7. A terminal structure of the type described comprising a grounded metal bracket having a base and an outwardly extending wall, a metal mounting plate extending transversely from said wall, a protector unit including protective devices and associated terminals accommodating incoming and outgoing conductor connections, means for detachably connecting said protector u'nit upon said plate, and flanges upon said plate for receiving said protector unit in a nested relation whereby to position said protector unit in a predetermined relation with respect to said plate and said wall.

8. A terminal structure of the type described comprising a bracket having a base and an outminals carried thereby, means for detachably connecting said protector unit upon said plate, and means for seating said protector unit whereby to position said protector unit in a prede-' termined position with respect to said plate and said outwardly extending wall.

9. A terminal structureof the type described comprising a mounting bracket having a base and an upstanding wall, a plate extending transversely from said upstanding wall, a protector unit including protective devices and associated terminals, means for detachably connecting said protector unit upon said plate, and flanges upon said plate for receiving said protector unit in a nested relation whereby to position said protector unit in a predetermined relation with respect to said plate and said Wall.

10. A terminal structure of the type described comprising a mounting bracket having a base and an upstanding wall, a plate extending transversely from said upstanding wall, a protector unit including protective devices and associated terminals, means for detachably connecting said protector unit upon said plate, and flanges upon said plate for receiving said protector unit in a nested relation whereby to position said protector unit in a predetermined relation with respect to said plate and said wall, said flanges extending at an angle from one face of said plate, one of said flanges being recessed to receive said protector unit, the other flange acting as a second point of support for said protector unit.

11. A terminal structure of the type described comprising a mounting plate, means for grounding said plate, a protector unit including protective devices and associated terminals, means upon said plate to embracingly seat said protector unit upon said plate in a predetermined relation, means for'detachably connecting said protector unit upon said plate in said predetermined relation comprising conductor means extending transversely through said protector unit and said mounting plate and forming certain of said terminals upon the opposite side of said mounting plate in insulated relation to said mounting plate.

JOHN S. BAKER.

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