Watthour meter socket adapter with safety shield

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates, in general, to electrical watthour meters and, specifically, to watthour meter mounting enclosures or socket adapters.

2. Description of the Art

Electrical power is supplied to an individual site or service by external electrical power line conductors located above or below ground. In a conventional arrangement, electrical power line conductors are connected to terminals in a watthour meter socket mounted on a building wall. Electrical load conductors are connected to another set of terminals in the meter socket and extend to the electrical distribution network in the building. A watthour meter is connected to both pairs of terminals in the meter socket to measure the electric power drawn through the load conductors.

Due to the current trend toward the use of plug-in watthour meters, A to S type socket adapters have been devised which convert A-base type bottom connected watthour meter sockets to receive plug-in watthour meters. Another type of socket adapter has been devised which allows the installation of other devices between the watthour meter socket and a plug-in watthour meter.

Such socket adapters employ a generally annular base having a shell joined thereto and extending outward from one side of the base. Jaw contacts are mounted in the shell and base. Each jaw contact has a female jaw portion disposed interiorly within the shell and a male blade terminal connected to the female jaw portion and extending outward through the base for plug-in connection to the terminals in the meter socket housing.

In previous watthour meter socket adapters, the jaw contacts were of two different constructions. In one construction, the jaw contacts have a folded over design formed of a base wall fixedly mounted by a fastener to the shell of the socket adapter and two spaced sidewalls extending therefrom. The outer ends of the sidewalls are folded over inwardly between the sidewalls and terminate in parallel end flanges which slidably receive a blade terminal of a watthour meter. A blade terminal is usually fixedly connected to the base wall of the jaw contact for connection to jaw contact in a meter socket.

In the second construction, the jaw contacts are formed of a generally planar terminal having opposed first and second ends. An angularly bent spring clip is riveted at one end to an intermediate portion of the terminal and extends to a contact edge disposed in separable engagement with the first end of the terminal to form a jaw for receiving the blade terminal of a watthour meter. The spring clip forcibly biases the watthour meter terminal into secure electrical engagement with the terminal. The second end of the blade terminal extends exteriorly from the base of the watthour meter socket adapter for releasable engagement in a socket jaw contact. A cotter pin is inserted through an intermediate aperture in the terminal to fixedly mount the terminal and jaw contact in position in the watthour meter socket adapter.

While it is typical for a watthour meter, once it is installed in a socket or socket and socket adapter, to remain in service for many years, it is still necessary for such meters to be removed for repair or replacement from time to time as well as to temporarily disconnect electrical service to a particular customer. During the installation and removal of the watthour meter from the socket or socket adapter, the electric power line terminals in the socket or socket adapter remain connected to the electric utility power line conductors and carry potential. The utility employee installing or removing the watthour meter may inadvertently touch such contacts thereby raising the possibility of injury. Furthermore, an inadvertent short across the contacts caused by a tool contacting the contacts or a full fault caused by a 90° offset insertion of the meter can cause a spark or flash which could damage the watthour meter installation as well as posing a significant risk of injury to the utility employee.

In U.S. Pat. No. 5,577,933, the present Applicants disclosed a unique safety shield for a watthour meter mounting apparatus which completely covered all of the exposed portions of the jaw contacts to prevent inadvertent contact with such contacts by the utility employee or by a tool.

One embodiment of this safety shield was in the form of a housing having a unitary sidewall and top wall defining a closed body with an internal recess surrounding the jaw contacts. Narrow apertures or slots were formed in the top wall for receiving a blade terminal of a watthour meter therethrough into engagement with a jaw contact disposed immediately below the aperture in the top wall of the safety shield. In another embodiment, a plurality of receptacles extend from a planar wall mountable in the socket adapter, with each receptacle having one or more slots for receiving the meter blade terminals therethrough. The individual receptacles were sized to completely surround at one jaw contact in the socket adapter.

In yet another embodiment, front and back plates surround the jaw contacts, conductors and the bottom mounted terminals. The front and back plates are joined by a number of fasteners or screws as well as two clips on the terminal portions of the plates.

The safety shield disclosed in U.S. Pat. No. 5,577,933 has proven to be an effective shield in preventing inadvertent contact with the jaw contacts. However, this safety shield is mounted to the bottom wall of a watthour meter socket adapter by means of fasteners extendable through apertures in the safety shield. This involves an additional assembly step and labor as well as additional components to fixedly mount the safety shield within the socket adapter which increase the cost of the socket adapter.

Thus, it would be desirable to provide an improved safety shield for a watthour meter socket adapter which may be easily mounted in and removed from a watthour meter socket adapter. It would also be desirable to provide an improved safety shield for a watthour meter socket adapter which can be releasibly mounted in a socket adapter by means of a snap-in connection.

SUMMARY OF THE INVENTION

One aspect of the present invention is a safety shield for a watthour meter socket adapter which is releasibly mountable in the housing of the socket adapter solely by a snap-in connection.

The housing of the watthour meter socket adapter having a base wall and an annular sidewall extending from the base wall. A plurality of jaw blades are mounted in the base wall and releasibly receiving blade terminals of a watthour meter and for removable insertion into jaw contacts in a watthour meter socket.

The safety shield covers substantially all of the electrical conductors and the exposed portions of the jaw blades within the socket adapter. The safety shield has at least one aperture alignable with one jaw blade for receiving a blade terminal of a watthour meter therethrough to engage the blade terminal with the jaw blade in the socket adapter.

Means are cooperatively formed on the housing and the safety shield for releasable snap-in mounting of the safety shield in the housing.

Preferably, the mounting means comprises a plurality of apertures formed in the housing a plurality of legs projecting from the safety shield, and a latch projection formed on each leg releasibly engagable in one aperture in the housing. Each leg cantilevers from a sidewall of the safety shield.

Each latch projection has a latch surface disposed at an acute angle with respect each leg.

In another aspect, a pair of flanges project oppositely from the sidewall of the safety shield. The legs project from each flange. Each flange extends substantially perpendicular from a sidewall of the safety shield. Each leg preferably extends angularly from each flange. In one embodiment, the apertures are formed in the base wall of the housing.

In another aspect, the apertures are formed in the sidewall of the housing spaced from the base wall. At least two apertures are formed in the sidewall of the housing, each having a latch projection formed therein.

At least two legs project from the safety shield. An aperture formed in each of the two legs is releasibly engagable with one latch projection in one aperture in the housing. The four apertures in the housing and the four legs on the shield are arranged two diagonally opposed pairs.

In another aspect, the safety shield is formed with depending portions which seat on the base of the socket adapter housing. At least one and preferably two surge ground conductors are mounted on the sidewall of the socket adapter housing and include at least one resilient finger which engages a recess formed in the safety shield in a snap-in connection to fixedly mount the safety shield in the socket adapter housing. Preferably each surge ground conductors has a pair of spaced fingers formed at opposite ends of each surge ground conductor. Each finger releasibly engages one recess of a pair of recesses formed on diametrically opposed side edges of the safety shield.

A raised boss is formed on the safety shield and disposed at each jaw contact location adjacent to one aperture formed in the safety shield. At least one portion of the raised boss has a freely movable end cantilevered from an opposite end fixed to the safety shield enabling the free end to pivot inwardly upon contact with a watthour meter inserted into the watthour meter socket adapter.

In conjunction with pairs of slots formed in the housing, the safety shield is also formed, in one embodiment, with pairs of slots which are alignable with the pairs of slots in the housing. In this arrangement, the slots in the safety shield engage upper portions of a circuit board extending perpendicularly from the base wall of the socket adapter housing. Further, the peripheral edge of the safety shield engages an outer edge of the circuit board for both covering and supporting the circuit board within the socket adapter housing.

In another aspect, a safety shield is provided for use with a current transformer rated watthour meter socket adapter having a plurality of potential jaw contacts receiving the potential jaw blades of a watthour meter. The safety shield may employ any of the latch mechanisms described above for fixed mounting in the socket adapter housing without the need for mechanical fasteners.

Also, the present invention includes unique support means formed in the base of the socket adapter for supporting a jaw contact. Spaced support posts are aligned with spaced wall members on the base. Each support post and each wall member includes a recess which receives a mating portion of the jaw blade contact for supporting the jaw blade contact on one aligned pair of a support post and a support wall.

Apertures are formed in the base of the socket adapter to receive a potential blade terminal. The jaw contact and the blade terminal, in one aspect, are separate from each other. In another aspect of the present invention, a three fingered jaw blade contact and the blade terminal are formed of a one-piece, unitary member.

In yet another aspect of the present invention, the separate three finger potential jaw contact and the separate blade terminal are interconnected in a unitary structure, while remaining electrically isolated from each other by means of a coupler which engages opposed side edges of one jaw contact and one blade terminal.

In yet another embodiment, the inventive safety shield can be adhesively fixed in the housing.

The safety shield of the present invention includes an easy and quick mounting arrangement for releasible mounting of the safety shield in the housing of the watthour meter socket adapter without requiring mechanical fasteners or additional assembly steps which have heretofore increased the manufacturing cost of a watthour meter socket adapter with a safety shield or the cost of the safety shield itself. The latch elements formed on the legs of the safety shield and the latch apertures or latch projections in the housing are integrally formed with the safety shield and the housing to eliminate the need for additional components necessary to mount the safety shield in the housing. In another aspect, the use of resilient fingers on the existing surge ground conductors to fixedly mount the safety shield in the housing also eliminates additional mechanical components.

BRIEF DESCRIPTION OF THE DRAWINGS

The various features, advantages and other uses of the present invention will become more apparent by referring to the following detailed description and drawing in which:

FIG. 1

is an exploded, perspective view showing one embodiment of a watthour meter socket adapter according to the present invention;

FIG. 2

is a perspective view of the watthour meter socket adapter shown in

FIG. 1

, with the dead front shield portion of the shell removed;

FIG. 3

is a partially broken-away, rear, perspective view of the shell of the socket adapter shown in

FIG. 1

;

FIG. 4

is a partially cross-sectioned, side view of

FIGS. 1 and 2

;

FIG. 5

is a perspective view of another embodiment of a jaw blade according to the present invention;

FIG. 6

is a partially cross sectioned, perspective view showing the mounting of the jaw blade depicted in

FIG. 5

in a watthour meter socket adapter extender housing constructed according to the present invention;

FIG. 7

is a perspective view of another embodiment of a safety shield according to the present invention;

FIG. 8

is an enlarged, partial, perspective view of

FIG. 7

showing the jaw contact safety shield mounting aperture and latch projection;

FIG. 9

is an enlarged, partial, perspective view of

FIG. 7

showing the interlocking of the safety shield with the latch projection depicted in

FIG. 8

;

FIG. 10

is a perspective view of yet another embodiment of a safety shield according to present invention;

FIG. 11

is a partial, enlarged, perspective view showing the interlocking of the safety shield of

FIG. 10

with the socket adapter housing depicted in

FIG. 6

;

FIG. 12

is a perspective view of another embodiment of a safety shield according to the present invention;

FIG. 13

is a partial, enlarged, perspective view showing the interlocking of the safety shield of

FIG. 12

in the socket adapter depicted in

FIG. 6

;

FIG. 14

is an enlarged, partial, perspective view showing a feature of the safety shields shown in

FIGS. 7

,

10

and

12

;

FIG. 15

is a perspective view of another embodiment of a safety shield according to the present invention;

FIG. 16

is a rear perspective view of a safety shield and a surge conductor shown in

FIG. 15

;

FIG. 17

is a partial, lateral, cross-sectional view showing the mounting of the safety shield and one surge ground conductor of

FIG. 16

in the socket adapter shown in

FIG. 15

;

FIG. 18

is an enlarged, partial, perspective view showing the interconnection of the spring fingers on the surge ground conductor with the safety shield shown in

FIG. 15

;

FIG. 19

is a plan view showing one embodiment of circuit board mounts in a socket adapter;

FIG. 20A

is a front elevational view of another embodiment of a watthour meter socket adapter housing according to the present invention with circuit board mounting means;

FIG. 20B

is a cross sectional view showing a power connection between a blade terminal and a circuit board mounted in the socket adapter of

FIG. 20A

;

FIG. 21A

is a perspective view of a printed circuit board mountable in the socket adapter according to the present invention;

FIG. 21B

is a perspective view of a modified printed circuit board according to the present invention;

FIG. 21C

is a perspective view of another embodiment of a printed circuit board according to the present invention;

FIG. 22

is a front perspective view showing the mounting of the circuit board of

FIG. 21

in a watthour meter socket adapter;

FIG. 23

is rear perspective view showing the printed circuit board and timer mounted in the socket adapter;

FIG. 24

is a perspective view of another embodiment of a safety shield according to the present invention usable with a current transformer rated watthour meter socket adapter;

FIG. 25

is a perspective view of another embodiment of a safety shield usable in a current transformer rated socket adapter;

FIG. 26

is a lateral cross-sectional view generally taken along lines

26

—

26

in

FIG. 25

;

FIG. 27

is a bottom perspective view of the safety shield shown in

FIGS. 25 and 26

;

FIG. 28

is a front perspective view of the socket adapter shown in

FIG. 25

, with the safety shield removed;

FIG. 29

is an enlarged, perspective view of a portion of the socket adapter shown in

FIG. 28

depicting the mounting of potential jaw contacts;

FIG. 30

is a perspective view showing the various jaw contacts, blade terminals and jaw blade terminals mounted in the socket adapter depicted in

FIG. 25

;

FIG. 31

is an exploded perspective view of a jaw contact and blade terminal coupler according to the present invention;

FIG. 32

is a perspective view of the assembled jaw contact and blade terminal coupler of

FIG. 31

of the present invention taken from a first side of the coupler; and

FIG. 33

is a perspective view of the assembled jaw contact and blade terminal coupler of

FIG. 31

taken from a second opposite side.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In order to better describe and appreciate the advantages of the present invention, a description of the conventional construction of an electric watthour meter socket adapter or socket extender/adapter, both hereafter referred to as a socket adapter, will be provided with reference to

FIGS. 1 and 2

. A conventional socket adapter

10

includes contacts designed to receive blade terminals of a conventional electric watthour meter, not shown, in a releasible connection. The socket adapter

10

includes terminals, described hereafter, which plug into mating contacts in a watthour meter socket. The number of contacts and terminals in the socket adapter

10

will vary depending upon the type of electric service at a particular user site,

FIG. 1

depicts, by way of example only, a single phase electric service.

As shown in

FIGS. 1

,

2

,

3

, and

4

, the socket adapter

10

includes a base portion

12

and a shell portion

14

which are fixedly joined together by suitable means, such as fasteners. The base

12

has a central wall

16

of generally circular shape. A plurality of generally rectangular bosses

18

are formed on the central wall

16

. Each of the bosses

18

has a slot

20

formed therein which extends completely through each boss

18

and the central wall

16

to receive a blade terminal therethrough, as described hereafter. A plurality of cylindrical bosses

22

are also formed on and extend outward from one surface of the central wall

16

. Through bores are formed in each boss

22

for receiving a fastener to join the shell

14

to the base

12

. A plurality of outwardly extending legs

24

are formed on a back surface of the central wall

16

and are provided in an appropriate number and spaced from one of the contacts or blade terminals which extends through the base

12

.

An annular, raised, inner peripheral edge flange

30

is formed on the base

12

and extends outward from one surface of the central wall

16

. An outer peripheral edge flange

32

is spaced radially outward from the inner flange

30

. A plurality of circumferentially spaced ribs

34

extend radially between the inner and outer peripheral edge flanges

30

and

32

.

The inner peripheral edge flange

30

includes an annular seat for receiving a peripheral edge portion of the shell

14

when the shell

14

is engaged with the base

12

. The outer peripheral edge flange

32

extends radially outward from the inner peripheral edge flange

30

and forms a mounting flange which mates with the mounting flange on the cover of the watthour meter socket, not shown. A conventional sealing ring, also not shown, is employed to surround and lockingly join the outer peripheral edge flange

32

to the mounting flange on the meter socket.

The shell

14

of the socket adapter

10

is formed with a generally annular sidewall

42

. The sidewall

42

terminates in an enlarged diameter exterior end mounting flange

44

. The mounting flange

44

is designed to mate with a corresponding mounting flange on a conventional watthour meter, not shown. A sealing ring, not shown, may be employed to encompass and lockingly connect the mounting flange

44

on the shell

14

and the mounting flange on a watthour meter.

The annular sidewall

42

of the shell

14

has an opposed annular edge

45

spaced from the exterior end mounting flange

44

. A generally solid wall

46

is integrally connected to the sidewall

42

by a plurality of flanges

43

and is spaced between the exterior mounting flange

44

and the opposed edge

45

. The wall

46

projects above the flanges

43

and acts as a dead front or safety shield covering all of the exposed portions of the jaw blades and an optional disconnect switch in a cavity between the base

12

and the shell

14

.

The wall

46

has a plurality of raised bosses

47

, each of which includes a slot

48

defining an opening for receiving a blade terminal

120

of an electrical device, such as a watthour meter, therethrough as shown in FIG.

11

. Each raised boss

47

extends a short distance above the generally planar wall

46

and forms a recess or cavity

49

on the back surface of the wall

46

which receives and locates a jaw blade mounted on the base

12

. Each slot

48

extends across the planar wall

46

and down a sidewall connecting the planar wall

46

to one flange

43

to permit easy angular insertion and removal of blade terminals through the slots

48

.

As shown in

FIG. 1

, at least one and preferably two identical surge ground conductors

220

are diametrically mounted opposite each other on the mounting flange

44

of the shell

14

. Each surge ground conductor

220

is removably mounted in one pair of slots in the mounting flange

44

and includes an arcuate wall portion

222

which conforms to the inner diameter of the annular sidewall

42

of the shell

14

. The arcuate wall portion

222

has an upper edge

224

and a lower edge

226

. A pair of radially extending tabs

228

are formed on opposite side ends of the arcuate wall portion

222

generally adjacent the upper edge

224

. Each tab

228

seats in the slots on the mounting flange

44

of the shell

14

. Each tab

228

has an upper edge disposed slightly above the upper edge of the mounting flange

44

. This places the upper edge of each surge ground conductor

220

at a position to electrically engage a ground terminal mounted on the rear surface of a conventional watthour meter.

Each surge ground conductor

220

, as shown in

FIG. 1

, has a mounting foot or tab

230

connected to the lower edge

226

of the arcuate wall portion

222

. The mounting foot

230

has a generally planar shape with apertures

232

positioned to receive fasteners to secure each surge ground conductor

220

to one of the bosses

22

in the base

12

. Each aperture

232

is formed as a stamped threaded aperture so as to receive a threaded screw without need for a nut.

FIGS. 1-4

depict a jaw blade

64

,

66

and a spring clip

100

which are depicted as but one example of a jaw contact or jaw blade assembly which can be employed in the socket adapter

10

. Further details concerning the construction and use of the jaw blade

64

,

66

and spring clip

100

can be had by referring to U.S. Pat. No. 6,152,764, the entire contents of which are incorporated herein by reference.

As shown in

FIG. 4

, a pair of load blade terminals

68

and

70

each comprise a generally planar member as is conventional in watthour meters and watthour meter socket adapters. One end of each load blade terminal

68

and

70

is connected to two internal bus bars within a disconnect switch

60

shown only by example in

FIGS. 1

,

2

and

4

. Outer ends

69

and

71

of the load blade terminals

68

and

70

have a length sufficient to enable the outer ends

69

and

71

to project through the bottom or central wall

16

of the base

12

exteriorally of the housing of the socket adapter

10

for insertion into mating jaw contacts in a watthour meter, not shown.

It will be understood that the following described load jaw blade structure may also alternately be employed for the line jaw blade structure or for both the line and load jaw blade structures in the socket adapter

10

.

By way of example, each of a pair of load jaw blades

64

and

66

, with only load jaw blade

64

being described in detail hereafter, includes a generally planar bus bar

74

which projects angularly and generally perpendicularly from the top surface of the housing of a switch

60

. The planar bus bar

74

has an opposed first and second ends

76

and

78

. Further, flange

80

projects angularly above and outward from the generally planar extent of the bus bar

74

to form a blade terminal guide as is conventional in watthour meter socket adapters.

The opposed load jaw blade

66

is identical to the load jaw blade

64

, but is formed of a mirror image to form a pair of left and right hand jaw blades

64

and

66

. However, the spring clip

100

mounted on the load jaw blade

66

is identical to the spring clip

100

used with jaw blade

64

.

A remotely controlled disconnect switch

60

, shown in

FIGS. 1

,

2

, and

4

as an option only, is located at the central wall

16

of the base

12

. The disconnect switch

60

may be any commercially disconnect switch which may include an internally movable member and at least one pair of contacts which are electrically connected between one of the pair of line and load jaw blades within the socket adapter

10

and the corresponding one of the pair of line and load blade terminals projecting outwardly from the socket adapter

10

and to certain jaw contacts in a watthour meter socket, not shown. The switch

60

may be remotely actuated by means of signals provided on wires

62

which extend exteriorally of the housing of the socket adapter

10

.

Referring now to

FIGS. 5 and 6

, there is depicted yet another embodiment of an electrical contact or jaw blade

526

. The jaw blade

526

has an elongated shape and is particularly suited for use in a socket adapter extender

528

shown in FIG.

6

. The socket adapter extender

528

is similar to the socket adapter

402

described hereafter with several modifications. The housing of the socket adapter extender

528

includes a generally planar base or bottom wall

530

and lower sidewall

532

. The sidewall

532

terminates at a radially outward extending mounting flange

534

. The mounting flange

534

has an inward extending, annular shelf

536

disposed interiorly within the socket adapter extender

528

and an outwardly extending flange terminating in a depending lip

538

spaced from the lower sidewall

532

. The lip

538

is positioned for receiving a sealing ring to mount the socket adapter extender

528

on a ring-style socket adapter cover, not shown. An upper sidewall

539

extends from the mounting flan

34

and terminates in a mounting flange.

The jaw blade

526

has a unitary, one piece construction formed of a blade terminal end

542

which is offset by an intermediate offset

544

from an elongated jaw contact end

546

. A blade terminal edge guide

548

is formed at one end of the jaw contact end

546

.

A pair of side flanges

550

and

552

project perpendicularly from opposite side edges of the jaw contact end

546

and extend from an upper end adjacent the blade terminal guide

548

and to an opposite end

554

approximate the intermediate offset

544

. The second end

554

of each side flange

550

and

552

seats on the base

530

of the socket adapter extender

528

to prevent sideways movement of the jaw blade

526

relative to the base

530

.

A conventional spring clip

558

is fixedly connected to the jaw contact end

546

by two fasteners, such as rivets, not shown, extendible through apertures

559

. The upper end of the spring clip

558

angles outwardly to form a mating blade terminal guide

548

on the jaw contact end

546

. The end

560

of the spring clip

558

is spaced from the adjacent jaw contact end

546

to define a slot for receiving a watthour meter blade terminal in a conventional manner.

Referring now to

FIGS. 7-9

, there is depicted a jaw contact safety shield

580

which is mountable in the socket adapter extender

528

. The safety shield

580

is formed of a one piece electrically insulating material, such as a suitable plastic, and is formed of an enclosure which, when the safety shield

580

is mounted in the socket adapter extender

528

, completely surrounds all of the line and load jaw blades within the socket adapter extender

528

except for small slots allowing the insertion of a watthour blade terminal into engagement with each line and load jaw blade.

The safety shield

580

includes a top or outer wall

582

and a plurality of sidewalls all denoted by reference number

584

. A plurality of raised bosses

586

are formed in the top wall

582

. The bosses

586

are positioned at the normal jaw contact positions of a watthour meter socket adapter.

Each boss

586

has an aperture or slot

588

formed therein. Each slot

588

has a top wall portion

590

extending parallel to the plane of the top wall

582

and a contiguous sidewall portion

592

forming a continuous L-shaped slot along the top wall

582

and the sidewall

584

of the safety shield

580

. The unique provision of the sidewall slot portion

592

simplifies the insertion and removal of a watthour meter into and out of the jaw contacts of the socket adapter extender

528

through the safety shield

580

.

A peripheral flange

594

extends outward from a lower edge of the sidewall

584

of the safety shield

580

. The peripheral flange

594

has a polygonal or square shape, by example only. Other shapes, such as octagonal, round, etc., may also be employed.

A plurality of legs

596

project from the peripheral flange

594

, generally at each corner of the peripheral flange

594

. Each leg

596

has a generally planar configuration with a notched inner surface

598

. A slot

600

is formed on the outer side of each leg

596

extending from the peripheral flange

594

to an aperture

602

in each leg

596

.

Latch means is provided for releasibly latching each leg

596

and the entire safety shield

580

in the socket adapter extender

528

. The latch means includes a plurality of apertures

604

formed in the lower sidewall

632

of the extender

528

adjacent to the mounting flange

534

as shown in

FIG. 8. A

latch projection

606

is unitarily formed with the sidewall

532

and projects outwardly therefrom. The latch projection

606

has a flat edge surface

608

for releasable engagement with the aperture

602

in each leg

596

as shown in FIG.

9

. As the legs

596

of the safety shield

580

are urged toward each latch projection

606

, the outer end of each leg

596

, which has an angled end surface

610

, rides along the latch projection

606

until the aperture

602

slides over the edge

608

of the latch projection

606

releasibly latching the leg

596

to the housing of the extender socket adapter

528

. Since the aperture

604

in the sidewall

532

opens outwardly underneath the mounting flange

534

, the legs

596

of the safety shield

580

may be released from the latch projection

606

by forcing a tool, such as a screwdriver, underneath the lower end of each leg

596

disengaging the leg

596

from the latch projection

606

.

A modified safety shield

620

, which is substantially similar to the safety shield

580

shown in

FIG. 7

is depicted in

FIGS. 10 and 11

. Accordingly, like reference numbers are used to identify like components in both of the safety shields

580

and

620

.

In this embodiment, the plurality of legs

622

are also located at the outer corners of the safety shield

620

. Each leg

622

terminates in an outwardly extending latch projection

624

which is positioned to engage an inner lip

626

formed in the sidewall

539

adjacent the mounting flange

532

as shown in

FIG. 11

to releasibly latch the safety shield

620

to the housing of the socket adapter extender

528

. The latch projection

624

is accessible from the bottom of the mounting

532

and can be urged radially inward from the mounting flange

532

to disengage the latch projection

624

from the lip

626

and enable the safety shield

620

to be removed from the extender

528

.

Referring now to

FIGS. 12 and 13

, there is depicted another embodiment of a jaw contact safety shield

630

which is particularly suited for use with a low profile socket adapter, not shown, having a short height sidewall. Again, since the safety shield

630

is similar to the safety shields

580

and

620

described above, like components are depicted by the same reference number. In this embodiment, a pair of spaced end flanges

632

are formed on opposite portions of the sidewalls

584

and project outwardly from the adjacent sidewall

584

. Each end flange

632

has a pair of downwardly depending legs

634

extending therefrom, each leg

634

terminating in an outwardly extending latch projection

636

. The latch projection

636

on each leg

634

in releasibly insertable through an aperture in the base and the adjacent ring of a socket adapter in the same manner as the latch projection

624

engages an aperture in the sidewall

539

, as shown in FIG.

11

.

As shown in detail in

FIG. 13

, each latch projection

636

snaps into engagement with an underlying surface

640

on the sidewall of the socket adapter housing to releasibly mount the safety shield

630

to the housing. Each latch projection

636

may be released from engagement with the back surface of the base

637

of the socket adapter by means of a sharp tool inserted from behind the base

637

.

FIGS. 12 and 14

depict a unique feature of the safety shields

630

,

580

and

620

. As shown therein, one leg

640

of the boss

586

adjacent to the slot

588

positioned at the eighth jaw contact position is cantilevered from an outer edge adjacent the sidewall

584

. This provides the cantilevered flange

640

with a freely movable end

642

which enables the flange

640

to bend inward about the outer edge in a watthour application where a single phase watthour meter has a potential clip at this position. The potential clip engages the flange

640

and bends it inward about the outer end enabling the watthour meter to properly seat in the socket adapter.

Referring now to

FIGS. 15-18

, there is depicted a modification to the above-described safety shield in which a safety shield

110

is mounted in the socket adapter extender

528

in a unique manner. Further, it will be understood that the safety shield

110

may also be employed in other types of socket adapter housing constructions.

The safety shield

110

is formed of a one piece, electrically insulating material and has a construction which, when mounted in the socket adapter extender

528

, completely surrounds and substantially encloses all of the line and load jaw blades within the socket adapter extender

528

except for small slots allowing the insertion of watthour blade terminals into engagement with each line and load jaw blades or contacts.

The safety shield

110

includes a top or outer wall

112

and a peripheral sidewall

114

depending therefrom. The top wall

112

and the sidewall

114

are depicted by example only as having a generally square configuration. A pair of opposed outwardly extending side edge flanges

116

and

118

project from the lower edges of two opposed sidewalls

114

. A pair of laterally extending flanges

120

and

122

project perpendicularly outward from opposed sidewalls

114

. An outer end of each lateral flange

120

and

122

communicates with perpendicular, downward depending sides

124

and

126

, respectively. The sides

124

and

126

are oriented, when the safety shield

110

is mounted with the socket adapter extender

528

, immediately adjacent to the inner wall of the surge ground conductors

128

and

130

, respectively.

A plurality of raised bosses

132

are formed in the top wall

112

and are located at the normal jaw contact positions of a watthour meter socket adapter. Each boss

132

has an aperture or slot

134

extending therethrough. As described above, the slots

134

extend over the top wall

112

and along the sidewall

114

to permit easy, angled insertion and/or removal of a watthour meter blade terminal into and out of contact with a jaw contact position behind each slot

132

.

A polygonal or rectangular shaped aperture

136

is formed in each lateral flange

120

and

122

for enabling mounting or access to a current transformer shorting switch

121

. The aperture

136

can also serve as a mounting window for any connector, such as a multi-pin connector, also not shown.

As shown in

FIGS. 15

,

17

and

18

, at least one and preferably two circumferentially spaced receivers or bosses

138

and

140

are formed on the outer edge of each lateral flange

120

and

122

and surround a flat

142

shown in FIG.

18

. The flat

142

is positioned approximately in line with one lateral flange

120

and

122

. Each boss

138

and

140

and the associated flat

142

form a radially outward opening cavity

144

.

The surge ground conductors

128

and

130

are identically constructed. The two ground surge conductors

128

and

130

are diametrically mounted opposite each other on the mounting flange

44

of the socket adapter extender

528

in a pair of slots

146

formed in the mounting flange

44

.

As clearly shown in

FIG. 16

, each surge ground conductor

128

and

130

includes an arcuate wall

148

which conforms to the inner diameter of the annular sidewall

539

of the socket adapter extender

528

. A pair of radially extending tabs

150

are formed on an upper edge

152

of each surge ground conductor

128

and

130

and seat within one of the slots

146

in the mounting flange

44

to support each surge ground conductor

128

and

130

from the mounting flange

44

of the socket adaptor extender

528

. The upper edge

152

of each surge ground conductor

128

and

130

overlays a portion of the mounting flange

44

and is in position to electrically engage a ground terminal mounted on the rear surface of a conventional watthour meter.

As shown in

FIG. 16

, each surge ground conductor

128

and

130

, has a lower mounting foot

154

which is formed as an extension of the arcuate sidewall

148

. The mounting foot

154

has a distal end

156

. An aperture

158

is formed within the mounting foot

154

and surrounds a tab

160

which integrally extends from the end

156

. In use, the mounting foot

154

is bent generally perpendicularly outward from the arcuate sidewall

148

, in a direction opposed to the radially inward extending direction of the tab

160

. This bending movement of the mounting foot

156

enables the mounting foot

154

to slide through an aperture formed in the sidewall

539

of the socket adapter extender

538

to secure the surge ground conductor

128

or

130

in position on the sidewall

139

of the socket adapter extender

528

.

According to a unique feature of the present invention, each surge ground conductor

128

and

130

is formed with at least one and preferably two arcuately spaced fingers

162

and

164

. Each pair of the spring fingers

162

and

164

has an angularly bent portion projecting away from the surface of the arcuate sidewall

148

. Each of the spring fingers

162

and

164

is spaced from opposite sides of the arcuate sidewall

148

as shown in FIG.

16

. The distal end of each of the spring fingers

162

and

164

is positioned to engage the cavity

144

formed by the boss

140

and the flat

142

in the lateral flanges

120

and

122

of the safety shield

110

to securely retain the safety shield

110

in position within the interior of the socket adapter

110

. In this mounting position shown in

FIG. 17

, the bottom edge of the arcuate sidewalls

148

directly seats on the interior ring of the socket adapter extender

528

. This mounting arrangement eliminates the use of any separate mechanical fasteners to fixedly mount the safety shield

110

within the interior of the socket adapter extender

528

. At the same time, the safety shield

110

can be easily removed by merely urging the distal ends of each of the spring fingers

162

and

164

radially outward until the distal ends of each spring finger

152

and

164

disengage from the flats

132

on the lateral flanges

120

and

122

in the safety shield

110

.

Referring now to

FIGS. 19

, there is depicted a socket adapter

400

which has means for mounting or supporting auxiliary components, such as generally planar circuit boards

653

, adjacent to or preferably on the base

402

. The mounting means comprises at least one pair and, preferably, a plurality of pairs of posts

650

which are arranged in diametrically opposed pairs. Each post

650

is formed at the juncture of the base

402

and the ring

406

of the socket adapter

400

and extends upward therefrom. A U-shaped channel

652

is formed in each post

650

. The U-shaped channel

652

in one post is linearly aligned with a U-shaped channel of a post

650

in one adjacent pair of posts

650

as shown in FIG.

19

. This arrangement forms a pair of channels

652

adjacent to the inner surface of the sidewall

412

of the socket adapter

400

.

Although the peripheral flange

594

of the shield

620

may be cut out or shortened to allow the circuit boards

653

mounted within the pairs of posts

650

to extend upward along side of the sidewall

592

of the shield

620

, in a preferred embodiment, as shown in

FIGS. 31 and 32

, a U-shaped slot

654

, one wall of which is shown in

FIGS. 31 and 32

, is integrally formed adjacent to opposite side edges of each leg

622

of the shield

620

and engage the upper end of a circuit board

653

disposed adjacent to each slot

654

. In this manner, the circuit board

653

is mounted in the channels

650

and slots

654

and is seated against the peripheral flange

594

of the shield

620

.

Also shown in

FIG. 19

is further modification to the socket adapter

400

, or more preferably, the socket adapter

528

, in which at least four and preferably more standoffs

656

are mounted on the base

402

of the socket adapter

400

for securing a circuit board, not shown, in a horizontal orientation between the line and load jaw blades

416

and

418

. Screws are insertable through apertures into the circuit board into the stand offs

656

.

FIG. 20A

shows a further modification to the socket adapter

400

in which the socket adapter

400

is devised for carrying one or more circuit boards

653

at various positions inside of the sidewall

412

. Although

FIG. 20A

depicts the pairs of posts

650

generally arranged in two diametrically opposed pairs, it will be understood that the embodiment shown in

FIG. 20A

need not necessarily include such posts

650

.

Auxiliary support members

658

,

660

and

662

are provided at various locations about the periphery of the sidewall

412

at the juncture of the sidewall

412

and the base

402

. In addition to a mounting function, the posts and support members also add strength to the sidewall-base joint of the one piece socket adapter housing.

The auxiliary support members may take a variety of forms as shown by the different support members

658

,

660

and

662

. The support members

658

,

660

and

662

all include at least one or more U-shaped slots

664

. The support members

658

,

660

and

662

are arranged in opposed pairs, as shown in

FIG. 20A

, by example only, such that one slot in one support member linearly aligns with one slot in an opposed support member. The pairs of aligned slots are thus capable of supporting opposite edges of a circuit board

653

oriented perpendicularly with respect to the base

402

of the socket adapter

400

. This enables many circuit boards

653

to be housed within the socket adapter

400

between the jaw contact ends of the line and load jaw blades

416

and

418

. The support members

658

,

660

and

662

may also be provided outside of the shield

620

to support a circuit board between the sidewall

412

and the sidewall

594

or the shield

620

.

Another aspect of the present is shown in

FIG. 20B

which depicts a printed circuit board

653

mounted between two aligned support members

650

and extending laterally across all of the line blade terminal receiving slots

404

in the base of the socket adapter

400

. An electrically conductive spring tab

655

is soldered or otherwise fixedly mounted on the printed circuit board

653

in electrical communication with conductive members of the circuit board

653

. The tab

655

extends outward from the printed circuit board

653

to a position which intersects with a line blade terminal

657

inserted through the slot

404

in the base of the socket adapter

400

. The tab

655

enables line power from the line blade terminal

657

to be applied to the printed circuit board

653

to power electrical components mounted on the printed circuit board

653

.

In addition to mounting circuit boards in a vertical, orientation between aligned pairs of slots along the periphery of the interior sidewall and base of the socket adapter extender

528

, one or more circuit boards may also be mounted between any two blade terminal apertures. A circuit board

168

, shown in

FIGS. 21A

,

22

and

23

, is mounted through the slots

170

and

172

in the base

530

which normally receive the fifth and sixth terminals of a watthour meter socket adapter, if present in a particular meter.

It will be understood, however, that the circuit board

168

could also be mounted between any pair of line and load contact receiving slots as described hereafter.

As clearly shown in

FIG. 21A

, the circuit board

168

has a conventional planar circuit board shape with a at least one and, preferably, a pair of depending terminal portions

174

and

176

which are sized to be slidably inserted through the slots

170

and

172

in the base

530

. Apertures

178

may be formed in each terminal end for receiving a cotter pin or other fastener to securely retain the printed circuit board

168

in position. Electrically conductive pads or terminals

179

such as a copper foil pad bonded to the circuit board, are carried on the legs

174

for connection to an electrical circuit or component external to the socket adapter

528

by a jaw connection, connector, solder or clamp connection.

The printed circuit board

168

may be used as a mounting surface for any electrical, electromechanical or electronic component or circuit which is used in a watthour meter socket adapter.

In addition to the use of fasteners or cotter pins extending through the aperture

178

in the terminal ends

174

and

176

, the circuit board

168

may also be secured in position by means of an engagement with the bent tab

160

on each surge ground conductor

128

and

130

shown in FIG.

16

. The tabs

160

are designed to slid into arcuate shaped notches

121

formed in opposed side edges of the printed circuit board

168

as shown in FIG.

21

A.

In one example of an application or use of the printed circuit board

168

, as shown in

FIGS. 22 and 23

, a timer

182

is mounted on the circuit board

168

. The timer

182

includes a face plate or dial

184

, shown in

FIG. 23

which is visible thorough an aperture

186

formed in the base

530

of the socket adapter extender

528

. A time display

188

as well as individual pushbuttons or switches

190

and

192

are also mounted on the dial

184

for controlling operation of the timer

182

, such as setting the current time, resetting the time. Event times may also be programmed via the switches

190

. An output signal from the timer

182

at one event time may energize one or more relays mounted on the circuit board

168

to control components within the socket adapter extender, such as a power disconnect switch, service limiter, etc., to break the circuit between the line and load contacts to shed loads, such as a hot water heater, at a preprogrammed time.

Referring now to

FIG. 21B

, there is depicted a modified circuit board

710

. The circuit board

710

can be mounted between any aligned pair of apertures in the base of a socket adapter, such as between the fifth and sixth terminal positions, or between any pair of line and load terminal positions. In this embodiment, the circuit board

710

is provided with a two pairs of apertures, not shown, located near the upper edge of the circuit board

710

. A conventional socket adapter jaw contact

712

is mounted to the circuit board

710

by means of fasteners extendable through apertures in the jaw contact

712

and the apertures in the circuit board

710

. Thus, the jaw contacts

712

can comprise a three finger jaw contact as shown in

FIG. 30

, and described hereafter. By way of example only, the jaw contact

712

comprises a pair of contact clips

714

which are mounted on opposite sides of the circuit board

710

in an aligned pair. Each of the clips

714

includes apertures alignable with the apertures in the circuit board

710

for receiving mechanical fasteners, such as rivets, therethrough to affix the contact clips

714

to the circuit board

710

. The contact clips

714

, on at least one side of the circuit board

710

, are electrically connected to conductive traces

716

conventionally formed in the circuit board

710

. A spring clip

718

is mounted on each contact clip

714

and has an end portion which biases the contacting portions of each contact clip

714

toward the opposed contact clip

714

to provide a secure electrically connection between the contact clip

714

and an inserted electrical terminal.

The contact clip

714

as well as the spring clip

716

may be formed as a one piece member having a single end portion. Alternately, as shown in

FIG. 21B

, each contact clip

714

and each spring clip

716

may be soldered to form two end portions. Further, the end portions of each contact clip

714

may be provided at different lengths to provide a staggered electrical terminal insertion force.

As also shown in

FIG. 21B

, the conductive pads

179

mounted on the terminal end portions

174

and

176

of the circuit board

710

are also electrically connected to conductive traces

720

carried on the circuit board

710

. Any electrical circuit or electrical component may also be mounted on the circuit board

710

and electrically connected to the conductive traces

716

and

720

in a conventional manner.

FIG. 21C

depicts a further modification to the circuit board

710

. In this aspect of the invention, each jaw contact clip

724

is mounted directly on the circuit board

710

such that the contact fingers of each contact clip

724

are spaced from a conductive pad

726

, such a copper foil pad, bonded or otherwise mounted on the circuit board

710

. In this aspect of the invention, each jaw contact clip

724

and opposed conductive pad

726

form a single jaw contact for receiving a blade terminal therebetween in electrical connection.

Further, the terminal end portions of the circuit board

710

, in this embodiment, may be formed solely by flat, electrically conductive plates

728

, such as copper-tin plates which are fixedly mounted to the circuit board

710

by means of fasteners, such as rivets mounted through aligned apertures in each plate

728

and the lower portion of the circuit board

710

. It is also feasible, in the present invention, to directly overlay the conductive plates

728

on the terminal portions

174

and

176

extending from the main portion of the printed circuit board

710

.

One or more relays may be mounted on the printed circuit board

710

, each relay including at least one switchable contact which is movable between a normally open and a normally closed position. The contact terminals can be electrically connected by separate wires or conductors or by means of conductive traces on the circuit board

710

between one jaw contact

712

and one plate terminal portion

179

in the embodiment shown in

FIG. 21B

or between one jaw contact

724

,

726

and one conductive terminal plate

728

in the embodiment shown in FIG.

21

C. The relay(s) can serve as a power disconnect or service limiter such that in normal operation, the relay contacts are closed allowing electrical current to flow between one jaw contact and one associated conductive plate or blade portion. However, when the relay(s) are activated, the contacts switch positions to an open position thereby opening or breaking the circuit between each jaw contact and blade terminal pair to disconnect electrical power to the use site.

Referring now to

FIG. 24

, there is depicted a safety shield

400

which is specifically designed for use in a current transformer rated watthour meter socket adapter

402

. In general, the safety shield

400

is similar to the safety shield

580

described above and shown in

FIG. 7

in that it includes a top wall

403

, a plurality of depending sidewalls

404

, and a peripheral flange

406

projecting generally perpendicularly outward from each sidewall

404

. A plurality of raised bosses

408

extend upward a slight distance above the surface of the top wall

403

and carry individual slots

410

opening to the interior of the shield

400

and providing access to jaw contacts mounted on the base of the socket adapter

402

. The top wall

403

is also formed with a plurality of laterally spaced dividers or walls

412

which form laterally spaced apertures

414

between adjacent dividers

412

. Further, in a centrally located, raised portion

416

, a plurality of laterally spaced slots

418

are formed to provide access to current transformed rated jaw contacts mounted within the socket adapter

402

, as described hereafter.

The safety shield

400

may be securely or fixedly mounted to the socket adapter

402

by any of the mounting or latch means described above for the safety shields

580

and

620

.

FIGS. 25 and 26

depict a modified safety shield

420

which is similar to the safety shield

400

in that it includes raised bosses

408

extending from a top wall

403

, slots

410

formed in each boss

408

, spaced dividers

412

forming laterally spaced apertures

414

, and a raised portion

416

carrying laterally spaced slots

418

. However, in this embodiment, the top wall

403

has a greater lateral extent so as to closely conform to the inner sidewall of the socket adapter

402

. A polygonal shaped aperture

422

is formed along one lateral side edge of the top wall

403

for receiving a current transformer shorting switch, or electrical pin connector, not shown.

Opposed pairs of raised bosses

424

formed along lateral opposed side edges of the top wall

403

and form recesses designed to receive spring fingers

162

and

164

on the surge ground conductors

128

and

130

in the same manner as described above and shown in

FIGS. 15-18

. In this manner, the spring fingers

162

and

164

on the surge ground conductors

128

and

130

fixedly, yet releasibly mount the safety shield

420

within the interior of the socket adapter

402

.

The safety shield

420

is formed with a pair of spaced arcuate sidewalls

428

and

430

which are diametrically opposed on opposite sides of the safety shield

420

. The arcuate sidewalls

428

and

430

are disposed adjacent to the arcuate wall portions

148

of the surge ground conductors

128

and

130

.

As shown in

FIG. 27

which depicts a rear or bottom view of the safety shield

420

, a rectangular frame

432

formed of four interconnected sidewalls projects from the rear surface of the top wall

403

of the safety shield

420

. The dividers

412

extend from the top to the bottom of the frame

432

and between opposed elongated sidewalls of the frame

432

. The frame

432

and spaced dividers

412

form a plurality of pairs of cavities, including the cavities

414

opening through the top wall

403

of the safety shield

420

and a plurality of interior cavities

434

opening to the slots

428

in the top wall

403

and defining a jaw contact mounting area.

The frame

432

also includes a first laterally extending wall

436

, a spaced second laterally extending wall

438

and a plurality of intermediate short walls

440

which extend between each of the dividers

412

. An enlargement

442

having a tapered or angled edge

444

on one side thereof facing the cavity in the frame

432

opening to the slots

418

. The angled or tapered surface

444

acts as a guide for urging the potential jaw contacts into the proper location within the cavity in the frame

432

into alignment with the slot

418

so as to be positioned to receive a blade terminal of a watthour meter inserted through the slot

418

.

FIGS. 28 and 29

depict interior views of the socket adapter

402

, with the shield

400

removed. As shown in

FIG. 28

, the socket adapter

402

includes the generally planar base

450

and an annular sidewall

452

projecting therefrom. A plurality of line and load watthour meter blade terminal receiving slots

454

are formed in the base

450

at the normal watthour meter blade terminal positions. In order to support auxiliary electrical contacts on the base

450

, a plurality of posts

456

are integrally formed with the base

450

and project generally perpendicularly therefrom. The posts

456

are disposed between the line and load jaw blade receiving slots

454

. The posts

456

have a generally square cross section extending from a common lower portion

458

and are laterally spaced across the base

450

.

An aperture

460

is formed in the top end of each post

456

for receiving a fastener or screw as described hereafter. Also, a notch

462

is formed in the outer end of each post

456

and has a configuration for receiving a planar flange on an electrical contact as described hereafter.

A barrier

464

is also formed on the base

450

and is spaced from the posts

456

. The barrier

464

also extends laterally across the base

450

and has a plurality of laterally spaced recesses

466

which divide the barrier into a plurality of walls

468

. Each wall

468

has a top edge

470

and a stepped recess formed on one side facing the posts

456

. The recess is formed with a first shallow notch

472

and a second, adjacent, deeper notch

474

.

A pad

476

is formed on the base

450

of the socket adapter

402

and extends between one post

456

and one wall

468

. A generally rectangular slot

478

is formed between two adjacent pads

476

. The slots

478

open through the base

450

of the socket adapter

402

and are sized to receive one end of a conventional blade terminal, as described hereafter.

Although each of the safety shields

110

,

400

420

,

580

,

620

and

630

have been described above as being releasibly mountable in a watthour meter socket adapter housing by a snap-in connection, it will be understood that each safety shield, instead of the snap-in connection, or in combination with the snap-in connection, may be more fixedly mounted in the housing of a socket adapter by applying adhesive between adjoining portions of each safety shield and adjacent wall surfaces of the socket adapter housing, or the wall portion

148

of the surge ground conductor

128

shown in FIG.

17

. While referring briefly to

FIG. 17

, adhesive can also be applied to the bottom edge of the safety shield

110

and the upper surface of the ring or collar formed on the inner surface of the sidewall

539

of the socket adapter

528

.

Before describing mounting of the electrical contacts on the posts

456

and walls

468

, a brief description of the construction of several configurations of electrical contacts will be provided.

One embodiment of an electrical contact

480

is shown in

FIGS. 29 and 30

. The electrical contacts

480

are identical to the three finger jaw contacts disclosed in U.S. Pat. No. 5,853,300, assigned to the Assignee of the present invention, the entire contents of which pertaining to the three finger contact construction are incorporated herein by reference.

In general, each contact

480

has a three finger jaw-type contact design formed of first and second outer legs

482

and

484

which extend linearly from a generally planar base

486

. Each of the legs

482

and

484

terminates in a angularly bent outer end portion, both of which extend in the same direction to one side of the base

486

. An intermediate leg

488

is disposed between the outer legs

482

and

484

and has a generally curved shape extending from the base

486

to an opposite side of the base

486

from the outer ends of the outer legs

482

and

484

. The outer ends of the intermediate leg

488

also curves or bends outward from one side of the base

486

to form, in conjunction with the legs

482

and

484

, a jaw contact which receives a blade terminal extending outward from the base of a watthour meter, not shown.

A wire crimp collar

490

formed of two angularly disposed, bendable flanges, extends from one end of the base

486

. The two flanges of wire crimp collar

490

are bendable into registry with one end of an external conductor, not shown, to electrically connect one end of the external conductor to the contact

480

. Alternately, solder may be used to connect the external conductor to the flanges of the wire crimp collar

490

.

A support flange

492

is formed contiguous with the base

486

and extends generally perpendicularly from an opposite end of the base

486

. A threaded aperture

494

is formed in the support flange

492

and is alignable with the aperture

460

on the top edge of one post

456

. A screw fastener, not shown, threadingly engages the aperture

494

on the support flange

492

and the aperture

460

in the post

456

to fixedly mount the jaw contact

480

on the base

450

of the socket adapter

402

. An external conductor, not shown, may also be connected to the support flange

492

by connecting the external conductor to the screw fastener extending through the aperture

494

in the support flange

492

. A washer may be interposed between the head of the screw fastener in the support flange

492

for secure electrical engagement of the external conductor with the support flange

492

.

Finally, a mounting tab

496

extends perpendicularly from an outer end of the support flange

492

. The mounting tab

496

provides a separate connection to another external electrical conductor, not shown, such as a conventional fast-on or quick connector which is fixedly attached to one end of an electrical conductor and slidable engaged over a complimentary formed mounting tab

496

to connect the external conductor to the contact

480

.

Referring again to

FIGS. 29 and 30

, one jaw contact

480

is mounted on one aligned pair of a post

456

and a wall

468

. One end of the base

486

projecting downward from the wire crimp collar

490

is seated in the deeper notch

474

in the wall

468

. Since the notch

474

extends only a short distance along the wall

468

from the top edge

470

, one end of the contact

480

is located such that the wire crimp collar

490

seats on the top edge

470

of the wall

468

and the support flange

492

rests on the top edge of the post

456

, with the end portion of the base

486

seated within the notch

462

in the post

456

.

A planar blade terminal

500

is associated with the contact

480

. The blade terminal

500

has a generally planar extent with intermediate shoulders

502

designed to seat on the base

450

of the socket adapter

402

, with the lower portion of the blade terminal

500

extending through one slot

478

in the base

450

. The blade terminal

500

is secured in position within the socket adapter

402

by means of a cotter pin, not shown.

Referring briefly to

FIGS. 24-27

, when the contact

480

is in the mounting position shown in

FIG. 29

, the legs

482

,

484

and

486

defining the contact itself are aligned with one slot

418

in the shield

400

thereby allowing a blade terminal from the watthour meter to be inserted through the slot

418

in the safety shield

400

into contact with the jaw contact legs

482

,

484

, and

486

. At the same time, the support flange

492

as well as the fast-on tab

496

are accessible through the aperture

418

in the shield

400

to allow electrical connections with external electrical conductors.

Referring again to

FIGS. 29 and 30

, there is depicted another embodiment of an electrical contact or blade terminal

504

which can be mounted in the socket adapter

402

. The jaw blade terminal

504

has a one-piece construction which combines the three finger jaw contact structure of the jaw contact

480

with an integral blade terminal similar to the separate blade terminal

500

. The three legs

482

,

484

, and

486

are shown in

FIG. 30

at one end of the elongated, planar bar

506

which is part of the jaw blade terminal

504

. Shoulders

502

are formed adjacent the blade terminal end of the jaw blade terminal

502

and seat on raised portions

508

extending between adjacent tabs

476

on the base

450

of the socket adapter

402

. One side edge of the upper portion of the planar bar

506

seat in the shallow notch

472

on the wall

468

. The opposite side edge of the upper portion of the planar bar

506

rests against the sidewall of a post

456

to position the jaw contact

504

between one post

456

and one wall

468

and to enable the jaw contact end of the jaw blade terminal

504

to be positioned below and accessible through one slot

418

in the shield

400

as shown in FIG.

26

.

Finally, a coupler

750

is depicted in

FIGS. 31-33

for joining an electrical contact

752

with a planar blade terminal

752

into a unitary construction which may be mounted as a unitary jaw blade terminal in the socket adapter

402

in the same manner as the jaw blade terminal

504

. The coupler

750

is formed of an electrically insulating material, such as a plastic, to electrically isolate the jaw contact

752

from the blade terminal

754

.

The jaw contact

752

is a modified version of jaw contact

480

and is essentially the same as the jaw contact

480

except that jaw contact

752

does not include the support flange

492

and fast-on tab

496

. For convenience, the three legs

482

,

484

and

488

forming the jaw portion of the jaw contact

752

are given the same reference numbers as the corresponding legs in the jaw contact

480

. Likewise, a wire crimp collar

490

projects from one end of a base

496

.

The coupler

750

is exemplary formed as a one piece, unitary body having a first elongated sidewall

756

, and an opposed shorter sidewall

758

which are interconnected by upper and lower center walls

760

and

762

, respectively, which are spaced apart along the length of the sidewalls

758

and

760

.

The upper center wall

760

has a generally U-shape formed of a center portion

764

which is offset or spaced from a pair of base flanges

766

and

768

projecting from the sidewalls

756

and

758

, respectively, as well as a pair of side flanges

770

and

772

which also project from the sidewalls

756

and

758

, respectively, to form a slot which receives the base

486

of the jaw contact

752

. The base flanges

766

and

768

, the side flanges

770

and

772

as well as the center portion

764

of the upper center wall

760

interact along with a slot

778

formed between a pair of spaced projections in the upper end of the sidewall

756

to securely support the jaw contact

752

in the coupler

750

. The slot

778

engages an outwardly projecting side edge

780

on the leg

482

of the jaw contact

752

.

The jaw contact

752

is also retained in place in the coupler

50

by means of a projection

782

which is formed on one end of a cantilevered, resilient arm

784

which projects from one end of the center wall

764

into an opening formed in the center portion

764

as shown in FIG.

31

. The projection

782

engages an aperture

785

in the base

486

of the jaw contact

752

.

The lower center wall

762

is spaced from inwardly projecting side flanges

788

and

790

formed on one end of the sidewalls

756

and

758

, respectively, to form openings which slidably receive the planar blade terminal

754

therein. A pair of raised dimples

792

spaced from one end of the blade terminal

754

snap over the center wall

762

of the coupler

750

to slidably trap the blade terminal

754

between an upper edge of the lower center wall

762

and inwardly facing projections on the sidewalls

756

and

758

. A cotter pin or other fastener may be inserted through an aperture

794

in the blade terminal

754

to more securely retain the blade terminal

754

in the coupler

750

.

Referring briefly to FIGS.

27

and

31

-

33

, a plurality of U-shaped channels

796

project from the back surface of the top wall

403

of the safety shield

420

. The U-shaped channels

796

are formed adjacent to one lateral leg of the frame

432

at one end of certain slots

410

in the safety shield

420

. The U-shaped channels slidably receive the upper end

798

of the sidewall

756

of the coupler

750

to accurately mount the coupler

750

with respect to one slot

410

in the safety shield

420

.

In summary, there has been disclosed a unique safety shield for use with a watthour meter socket adapter or socket adapter extender which provides a dead front to isolate all current carrying components of the socket adapter from contact while still enabling the blade terminals of a watthour meter to be easily inserted through apertures in the safety shield into engagement with jaw contacts mounted within the socket adapter. The safety shield of the present invention is mounted in the socket adapter by means of snap-on clips and projections thereby eliminating the need for separate mechanical fasteners to simplify the assembly of the socket adapter and safety shield as well as reducing material costs. In one aspect, the safety shield is held within a fixed position within the socket adapter housing by means of spring fingers formed on the surge ground conductors to again eliminate the need for separate mechanical fasteners needed to fixedly mount the safety shield in the socket adapter.

A unique safety shield is disclosed for use with a current transformer rated socket adapter. The current transformer rated socket adapter is provided with mounting supports for accurately positioning potential jaw contacts and blade terminals to receive the potential blade terminals of the watthour meter and to interconnect with potential jaw contacts in a watthour meter socket.

In another aspect of the invention, the use of the one-piece coupler provides isolation of the jaw contact from the blade terminal while coupling the jaw contact and blade terminal into a unitary one-piece construction for ease of installation, reduced assembly steps and labor in mounting the jaw contact and blade terminal in a socket adapter. The coupler provides easy separate connections to the jaw contact and blade terminal for interconnection to a fuse, relay, etc., to provide special control features in the socket adapter. In addition, the coupler slides into the housing and does not require fasteners for mounting in the housing in the socket adapter or special mounting features on the jaw contact and blade terminal.

Number	Name	Date
RE. 34531	Bell et al.	Feb 1994
1645539	Mau	Oct 1927
3061763	Ekstrom	Oct 1962
3221216	Kobryner	Nov 1965
3662224	Rauch	May 1972
4127924	Koss	Dec 1978
4412714	Morningstart et al.	Nov 1983
4772213	Bell et al.	Sep 1988
4892485	Patton	Jan 1990
5023747	Lindsay	Jun 1991
5068962	Germer et al.	Dec 1991
5088004	Howell	Feb 1992
5145403	Schaffert et al.	Sep 1992
5423695	Robinson et al.	Jun 1995
5571031	Robinson et al.	Nov 1996
5577933	Robinson et al.	Nov 1996
5586913	Robinson et al.	Dec 1996
5704804	Robinson et al.	Jan 1998
6104586	Robinson	Aug 2000

	Number	Date	Country
Parent	09/148253	Sep 1998	US
Child	09/291885		US

Watthour meter socket adapter with safety shield

Information

Patent Number

Date Filed

Date Issued

Inventors

Original Assignees

Examiners

Agents

CPC

US Classifications

Field of Search

US

International Classifications

Abstract

Description

Claims

CROSS REFERENCE TO RELATED APPLICATION

US Referenced Citations (19)

Continuations (1)