Modular electrical disconnect switch

A modular electrical disconnect switch employs multi-functional component designs for minimum inventory of operating components. The switch replaces a number of switches of different ratings and sizes thereby reducing the total switch inventory requirements.

BACKGROUND OF THE INVENTION 
Simple electric disconnect switches consisting of a pair of separable 
contacts that are operated on by means of an operating mechanism under the 
control of a pair of powerful overcenter operating springs are described 
within an early U.S. Pat. No. 3,424,882. To maintain electrical connection 
when a contact blade and blade receivers are substituted for the contacts, 
a contact clip such as that described within U.S. Pat. No. 3,917,920 is 
employed. U.S. Pat. No. 4,675,481 entitled "Compact Electric Safety 
Switch" describes the advanced state of the art of disconnect switches 
employing a contact blade driven by a pair of powerful operating springs. 
With the rising cost of the ferrous and non-ferrous metals required within 
electric disconnect switches, it is imperative for U.S. manufacturers to 
reduce the number of inventoried switch component parts to remain 
competitive with offshore switch manufacturers. 
One purpose of the instant invention is to describe an electric disconnect 
switch that multi-functionally employs common components for the line and 
load terminal assemblies to reduce the number of parts that must be 
inventoried by the switch manufacturer. 
A further purpose of the instant invention is to describe a multi-rated 
electric disconnect switch that meets the electrical requirements of a 
number of separate electric disconnect switches. The multiple rating 
reduces the different types of switches that must be inventoried to meet 
the electric switch industry requirements. 
SUMMARY OF THE INVENTION 
The invention comprises an electric disconnect switch wherein a pivotal 
contact blade and blade receiver design meet the electrical requirements 
of several types of separate electric disconnect switches. A T-shaped lug 
adapter design multi-functionally fits within both line and load 
subassemblies.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The disconnect switch 19 according to the invention is shown in FIG. 1 to 
include a molded plastic support base 10. The current path through the 
switch includes a pair of load lugs 73 supported on the base by means of a 
blade carrier 54 and a contact blade 53 which connects the line lugs 72 
through a blade receiver 64. The contact blade connects with a pair of 
mechanism side frames 22, 23 by means of a pivot pin 60 and pivot arms 24, 
25. The side frames in combination with pivot arms 24, 25 and operating 
springs 39, 40 constitute the "operating mechanism" for lifting the 
contact blade 53 out of the blade receiver 64 to interrupt the current 
path between the load and line lugs 73, 72. 
The switch 19 is assembled in the manner depicted in FIG. 2 wherein the 
base 10 is formed from a single molding operation wherein the load lug 
compartment 15 and line lug compartment 14 are integrally formed 
upstanding from a planar bottom member 42. Also integrally formed with the 
base 10 is the blade receiver compartment 18 to which a separate arc 
chamber 17 is attached. A continuous blade clearance slot 9 is formed 
through both the arc chamber and the blade receiver compartments. Besides 
containing a part of the blade receiver 64, within the blade receiver 
compartment 18 and the arc chute assembly 69 within the arc chamber 17, 
the operating mechanism support 16 carries the side frames 22, 23 which 
are attached thereto by means of thru-holes formed within their bottom 
offset ends 36, 37 and threaded holes 38 formed within the bottom of the 
pivot support 16. The curved upper ends 32, 33 of the side frames 22, 23 
are captured within a corresponding pair of grooves 34, 35 formed on the 
top surface of the pivot support 16. The pivot pins 28, 29 pivotally 
support the spring guide arms 24, 25 and are in turn captured within the 
side frames by means of the pivot pin ends 28A, 29A. A pair of powerful 
operating springs 39, 40 are captured between the yokes 26, 27 formed on 
one end of the arms 24, 25 and the pivot pins 28, 29 extending through an 
opposite end thereof. The handle yoke 20, angled connector 21 and yoke 
plate 61 are pivotally attached to the bottom 42 by means of brackets 43 
which are fixedly attached to the bottom by means of thruholes 51, 52 and 
self-tapping screws 109. The handle yoke 20 is pivotally attached to the 
brackets 43, 44 by means of thru-holes 47, 48 formed through the handle 
yoke 20, yoke plate 61, angled connector 21, and thru-holes 49, 50 formed 
within the brackets, all by means of pivot pins 45, 46. The blade carrier 
54 includes a pair of side plates 58, 59 within which a T-shaped lug 
adapter 62 is inserted at one end and within which the contact blade 53 is 
inserted at an opposite end thereof. The contact blade is pivotally 
retained within the side plates 58, 59 by the insertion of a pivot pin 55 
through a slot 56 which extends through both of the side plates. The blade 
carrier 54 extends through the slot 110 such that the horizontal part 62A 
of the T-shaped lug adapter 62 seats on the platform 111 integrally formed 
within the load lug compartment 15 and is attached thereto by means of 
thru-holes 113 extending through the T-shaped lug adapter and thru-holes 
112 formed within the platform 111. To insure good electrical connection 
between the contact blades 53 the side plates 58, 59 a contact clip 57 is 
positioned over the side plates. The clip is similar to that described 
within the aforementioned U.S. Pat. No. 3,917,920. The contact blade 53 
extends through the slot 9 provided within the operating mechanism support 
16. The blade receiver 64 which includes a similar T-shaped lug adapter 
63, positioned inverse to the earlier described T-shaped lug adapter 62, 
such that the horizontal part 63A rests on the bottom 42 and is secured 
thereto by means of screws 117, thru-holes 115 formed through the T-shaped 
lug adapter 63 and threaded openings 116 formed within the bottom 42. A 
contact clip 67 similar to the earlier described clip 57 is positioned 
around the side plates 65, 66 within the blade receiver 64 to insure good 
electrical connection between the edge 53A of the contact blade 53 when 
inserted between the side plates 65, 66. An arc runner 68 is positioned on 
top of the blade receiver 64 to interact with the arc which occurs when 
the edge 53A of the contact blade is separated from the blade receiver 
while the switch 19 is electrically energized. The arc runner directs the 
arc within the arc chute 69 positioned within the arc chamber 17 wherein 
the arc becomes extinguished. An insulative cover 70 is fastened to the 
top of the pivot support 16 to confine the arc within the arc chute 69 
while allowing free movement of the contact blade 53 by means of clearance 
slot 71 formed therein. Once the blade receiver 64 is fastened to the 
bottom 42, a pair of line lugs 72 are fastened to the horizontal part 63A 
by means of thru-holes 74 formed through the line lugs 72, screws 120 and 
threaded openings 119. The load lugs 73 are attached to the blade carrier 
54 by means of thru-holes 75 formed in the load lugs 73, threaded holes 77 
formed in the horizontal part 62A of the T-shaped lug adapter 62 and 
screws 121. 
The current through the switch 19 in FIG. 1, traverses the current path 
assembly 89 best seen by referring now to FIG. 3. As described earlier, 
the current path comprises the line strap unit 90 and the load strap unit 
91 bridged by the contact blade 53. The line strap unit 90 is assembled 
around the T-shaped lug adapter 63 to which the side plates 65, 66 are 
attached along with the arc runner 68 by placing the bolt 85 through the 
thru-holes 82, 83, 84, 88 formed within the arc runner, side plates and 
the vertical plate 81 extending from the planar surface 63A of the 
T-shaped lug adapter 63 and attaching washer 129 and nut 130 thereto. The 
side plates 65, 66 are provided with bevelled surfaces 65A, 66A to 
facilitate the insertion of the edge 53A of the contact blade 53 and a 
projection 122 is formed on the inner surface of side plate 65, which 
extends through a slot 123 formed in the vertical plate 81 and an opening 
124 formed in the other side plate 66 to locate the side plate in the 
exact location on the T-shaped lug adapter 63. The vertical plate 81 
precisely sets the spacing between the side plates for receiving the 
contact blade edge 53A while the contact clip 67 insures good electrical 
continuity between the side plates and the contact blade 53 as described 
earlier. The end of the contact blade 53, opposite the contact blade edge 
53A, is pivotally arranged between the opposing side plates 58, 59 and is 
pivotally attached thereto by means of thru-holes 93, 94 through their 
respective side plates 58, 59 and the thru hole 92 within the contact 
blade 53 and by means of the pivot pin 55. The side plates 58, 59 are 
attached to the T-shaped lug adapter 62 by positioning on either side of 
the vertical plate 80 and the exact positioning of the plates on the 
T-shaped lug adapter 62 is insured by means of the projection 125 on side 
plate 58, slot 127 formed on the vertical plate 80 and thru-hole 126 
within the side plate 59. The spacing between the side plates is governed 
by the thickness of the vertical plate 80 and the side plates are attached 
to the vertical plate by means of openings 96, 97 in the side plates, 
thru-hole 95 formed within the vertical plate and by means of bolt 98, 
washers 99, 100 and nut 101. To insure good electrical continuity between 
the side plates and the contact blade 53 a contact clip 57 is arranged 
over the side plates in the manner similar to that described with respect 
to the contact clip 67 used with the line strap unit 90. A pair of load 
lugs 73 can be attached to the horizontal plate 78 for an unfused current 
path or alternatively, a fuse clamp 105 can be attached to the horizontal 
plate 78 by means of bolts 106, washers 107, thru-holes 108 in the fuse 
clamp 105 and threaded openings 128 formed within the horizontal plate 78. 
The current path assembly 89 depicted in FIG. 3, when assembled, replaces a 
fused and non-fused disconnect switch rated at 600 amperes, 240 volts, as 
described earlier and as shown for example in U.S. Pat. No. 3,211,867 and 
for a fused and non-fused disconnect switch rated at 600 amperes, 600 
volts, which have similar operating components but which are oversized to 
meet the increased voltage rating. The total number of parts for each 
switch is approximately the same and the number of "unique" parts, that 
is, parts that are different in size and shape is approximately 76. The 
number of parts required to manufacture the electric switch according to 
the instant invention is approximately the same as for either the 240 volt 
or 600 volt switches rated at 600 amperes. However, the number of unique 
parts for the switch of the instant invention is only 27 compared with 270 
total unique parts for the 240 volt and 600 volt switches. By comparing 
the line and load lugs 72, 73, T-shaped line and load lug adapters 62, 63 
and line and load contact clips 57, 67 it is noted that the parts are 
identical and hence substantially simplify both the inventory and assembly 
requirements. Side plate 66 is the mirror image of side plate 59 while the 
side plate 65 is the mirror image of side plate 58 thereby reducing the 
total number of such parts to be inventoried by 50 percent. 
It has thus been seen that by designing an electric disconnect switch 
having multi-functional components, that a substantial savings in the 
economics of the manufacture and inventory of the switch component parts 
can be realized.