US 3657723 A
The insulator comprises three molded segments which are mounted in interlocked end-to-end relation along the drive bar. The two end segments are of fixed length, and the intermediate segment is selectable in length depending upon the length of the drive bar which in turn depends upon the width of the switch. The segments are generally U-shaped in transverse cross-section, and are held in position on the drive bar by a flexible strip of insulating material inserted between spaced shoulders on the end segments after the segments are placed on drive bar. Arc shields may be secured to either or both of the end segments.
Claims available in
Description (OCR text may contain errors)
United States Patent Rys 1451 Apr. 18, 1972 s41 SEGMENTED INSULATOR FOR 2,098,579 11/1937 Hanny ..200/162 CONTACT BLADE DRIVE BAR OF A MANUAL SWITCH FOREIGN PATElJTS OR APPLICATIONS  Inventor: Tadeusz J. y Lexington y 1,024,606 2/1958 Germany ..200/ 162  Assignee: Square D Company, Park Ridge, Ill. Prim y Truhe Assistant Examiner-Gale R. Peterson Flledi P 9, 1970 Attorney-Harold J. Rathbun and Paul J. Rose  Appl. No.: 26,917 ABSTRACT The insulator comprises three molded segments which are "200/166 mounted in interlocked end-to-end relation along the drive  Field I I i v A 17 bar. The two end segments are of fixed length, and the inter- 174/5 138 mediate segment is selectable in length depending upon the length of the drive bar which in turn depends upon the width  References cued of the switch. The segments are generally U-shaped in transverse cross-section, and are held in positlon on the drive bar UNITED STATES PATENTS by a flexible strip of insulating material inserted between spaced shoulders on the end segments after the segments are 2,359,159 9/1944 Samzehus ..200/[62 placed on drive ban Arc shields may be secured to either or 3,202,775 8/1965 Tillson ..200/6 both f h end segments 3,133,984 5/1964 Farough et al... ..l74/5 2,871,282 l/1959 Tipsord et al ..l74/5 9 Claims, 5 Drawing Figures I9 2 3 40 U s s 2 1 "1 1 |4 T l i r l 1 x 1 4 C A: I =7};L 1i i 3 B 1k; 1 29 32 F L 3 36 34 I .11 i
1%; i 1 ltz ON 18 1,- .1
Patented April 18, 1972 2 Sheets-Sheet 2 INVENTOR.
TADEUSZ J. RYS
SEGMENTED INSULATOR FOR CONTACI BLADE DRIVE BAR OF A MANUAL SWITCH This invention relates to an improved insulator for the contact blade drive bar or actuating member of a multipole, snapaction, enclosed switch, and more particularly to a composite drive bar insulator of readily selectable length for use in switches having difierent numbers of poles or different spacing between the poles.
Generally, a multipole enclosed switch of the type for which this invention is best suited includes a pivoted contact blade drive bar driven by a manually actuated, snap-action mechanism to move two or more movable contact blades into and out of respective stationary contact jaws. In such switches,
insulation must of course be interposed between the contact blades and the drive bar, and the insulator used for this purpose must be rigid and must be formed of a tough and rugged material to withstand the forces imposed upon it as the contact blades are driven against the resistance imposed upon them by the contact jaws. In order to provide shoulder areas for engagement with the contact blades, the insulators cannot be of uniform transverse cross section throughout their length. Previously, such insulators were molded in one piece from a suitable molding material, and the molding and stocking costs were inordinately high because of the necessity of having the insulators available in different length to cover a full range of switch sizes.
An object of the present invention to provide an improved insulator for a contact blade drive bar, the insulator being segmented so as to have two identical end segments each of nonunifonn transverse cross section and useable in a switch of any width and an intermediate segment of uniform cross section selectable from a group of intermediate segments to provide a composite insulator of proper length for a specific switch.
Another object is to provide an improved insulator for a contact blade drive bar, the insulator comprising two end segments and an intermediate segment in interlocked end-to-end engagement, the intermediate segment being of uniform cross section so that it may be cut in any desired length from a long piece of molded material.
A further object of the invention is to provide an improved means for securing an insulator to a contact blade drive bar.
Other objects of the invention will become apparent from the following specification wherein reference is made to the accompanying drawings, in which:
FIG. 1 is a plan view of a segmented insulator in accordance with this invention mounted on a contact blade drive bar;
FIGS. 2 and 3 are sectional views respectively taken generally along the lines 2-2 and 3-3 of FIG. 1, FIG. 3 being drawn to a larger scale than FIG. 2;
FIG. 4 is a fragmentary view of an end segment of the insulator as viewed from the bottom of FIG. 2 and having the same scale as FIG. 3; and
FIG. 5 is an exploded view of the insulator and drive bar of FIG. 1.
Referring to the drawings, a segmented insulator 12 in accordance with this invention is shown as used on a drive bar 14 in driving engagement with three movable contact blades 15 of a heavy duty enclosed switch such as, for example, the switch disclosed in US. Pat. No. 3,339,047 issued Aug. 29, 1967 in the names of Tadeusz J. Rys et al.
The drive bar 14 is generally U-shaped and comprises an elongated cylindrical driving portion 14a, a first flattened mounting leg portion 14b extending generally at a right angle ranged in interlocked end-for-end engagement. Each of the insulator segments 19, 20, and 21 is generally U-shaped in transverse cross-section and each has a continuous longitudinal channel 22. When the segments are assembled on the drive bar, the channels 22 are aligned and receive the driving portion 14a. As shown best in FIG. 2 and 3, each of the channels 22 is curved at its inner end portion complementary to the driving portion 14a.
The intermediate segment 21 is of uniform transverse cross section throughout its length and, as shown in FIG. 3, the channel 22 thereof opens into an enlarged outer recess 24 defined by a pair of opposite wall portions 25 and forming a pair of shoulders 26 on opposite sides of the channel 22. As will be described hereinafter in more detail, a flexible retaining strip 28 is received in the recess 24 between the wall portions 25 and abuts the shoulders 26.
Each of the identical end segments 19 and 20 has an outer flange 29 provided with a peripheral groove 30 which may receive an edge portion of an arc shield 31, a short adjacent section 32 of the same cross-sectional size as, and shaped like, the intermediate segment 21, a shoulder-providing reinforcing ridge 34 between the section 32 and a section 35 of reduced cross-section, and a second, substantially larger, reinforcing ridge 36 at the other end of the section 35 and surrounding an axially directed socket 38 which is complementary to and which receives an end portion of the intermediate segment 21 Y to retain the intermediate segment 21 in position as will to the driving portion 14a at the left end thereof and having a hole therein for the reception of a pivot pin 16 carried by a mounting bracket 18, and a second leg portion 140 extending generally at a right angle to the driving portion 14a at the right end thereof, the leg portion 14c being connectable for movement by an operating handle (not shown) in a manner well known in the art and as shown, for example, in the aforementioned patent.
The segmented insulator 12 comprises two identical outer or end segments 19 and 20 and an intermediate segment 21ar' become apparent. The segments 19 and 20 are thus of nonuniform transverse cross section.
As shown best in FIG. 5, one of the flexible arc shields 31 is received in the peripheral groove 30 of the flange 29 of the end segment 19 and is retained on the flange by the lower edges 31a of a pair of opposing slots 31b in the arc shield. Another arc shield 31 may be similarly received in the grooves 30 of the flange 29 of the end segment 20 if desired and as indicated in FIG. 1.
The reduced section 35 of each of the end segments 19 and 20 has relatively flat outer side walls 39 which are parallel to each other, and a pair of generally flat inwardly directed platelike ledge portions 40 extending longitudinally between the ridges 34 and 36 coextensive with the length of the section 35.
An inner edge portion of each of the ledge portions 40 extends inwardly into a recess 41, similar to the recess 24 of the segment 21, and slots 43 (FIG. 5) open respectively through the walls 39 above the respective ledge portions 40. In each of the segments 19 and 20, the upper surfaces of the ledge portions 40 are spaced from the plane of respective shoulders 42 on opposite sides of the channel 22 and defined by the recess 41. Although the ledge portions 40 do not extend beyond the lower outer edges of the respective side walls 39, the ledge portion 40 and the shoulders 42 form groovelike spaces 44. Edge portions of the flexible strip 28 are snugly received in the spaces 44.
In the embodiment disclosed, the outer segments 19 and 20 are relatively shorter than the intermediate segment 21. However, the length of the intermediate segment 21 depends upon the width of the particular switch and thus may be longer or shorter than shown. Because the segment 21 is of uniform cross section, it may readily be made to have any desired length by cutting it from a long piece of molded material.
To assemble the composite insulator 12 on the drive bar portion 140, the opposite ends of the intermediate segment 21 are inserted into the sockets 38 of the respective end segments 19 and 20 with the channels 22 aligned, thereby interlocking segments 19, 20, and 21 to restrain them against transverse motion. The portion 14a of the drive bar 14 is inserted into the now aligned channels 22, and the flexible strip 28 is slid lengthwise between the shoulders 42 and the upper surfaces of the ledge portions 40. The flexible strip 28 thus retains the segments 19, 20 and 21 in position on the blade driving portion 14a. Longitudinal movement of the segments 19, 20, and 21 is prevented by engagement of the ridges 34 of the segments 19 and 20 with respective outer two of the contact blades 15.
Having thus describing my invention, 1 claim:
1. An electrical switch assembly comprising a pivotable drive bar having a driving portion, a plurality of generally flat switch blades pivotally mounted in spaced parallel relation and movable upon movement of the drive bar, each of the switch blades having a generally U-shaped edge portion defining a recess, and a segmented insulator including a plurality of rigid elongated insulator segments each having a generally U- shaped cross section partially defined by a pair of spaced opposite side walls and each being disposed in the recess of at least one of the switch blades and having an outer surface portion substantially complementary to and in engagement with the edge portion defining the recess, the insulator segments extending in aligned end-to-end abutting relationship in a row along. the driving portion of the drive bar, the driving portion being disposed within the insulator segments between the side walls thereof, two of the insulator segments being substantially identical end segments of non-uniform cross section and predetermined length and being positioned respectively at opposite ends of the row, and a third insulator segment being an intermediate segment of uniform cross section and of a length selected in accordance with the number and spacing of the switch blades.
2. An electrical switch assembly as claimed in claim 1 wherein end faces of adjacent ones of the segments have interlocking means for restraining the segments against transverse movement with respect to each other.
3. An electrical switch assembly as claimed in claim 2 wherein the interlocking means comprises a socket in one end portion of each of the end segments for receiving an end portion of the intermediate segment.
4. An electrical switch assembly as claimed in claim 3 wherein a first peripheral ridge on each end segment surrounds the socket thereof, and a second peripheral ridge on each end segment is longitudinally spaced from the first peripheral ridge thereon, each of the'second ridges providing shoulder portions for engaging the respective contact blades of the switch to restrain longitudinal movement of the insulator.
5. An electrical switch assembly as claimed in claim 1 wherein retaining means are provided for retaining the segments on the drive bar.
6. An electrical switch assembly as claimed in claim 5 wherein the retaining means comprises a pair of spaced shoulder portions formed on each of the end segments respectively on the side walls thereof, and a flexible strip of insulating material having outer edge portions thereof received snugly between the pairs of shoulder portions.
7. An electrical switch assembly as claimed in claim 6 wherein the U-shaped cross section of each of said segments defines a channel portion for each of said segments and the respective channel portions are recessed for receiving the flexible insulating strip, and the shoulder portions are in the recesses of the end segments.
8. An electrical switch assembly as claimed in claim 7 wherein the shoulder portions are defined by the bottoms of the recesses and ledge portions extend into the recesses from opposite sides thereof.
9. An electrical switch assembly comprising a pivotable drive bar having a driving portion, a plurality of generally flat switch blades pivotally mounted in spaced parallel relation and movable upon movement of the drive bar, each of the switch blades having a generally U-shaped edge portion defining a recess, and a segmented insulator including a plurality of rigid elongated insulator segments each having a generally U shaped cross section partially defined by a pair of spaced opposite side walls and each being disposed in the reces of at least one of the switch blades and having an outer surface portion substantially complementary to and in engagement with the edge portion defining the recess, the insulator segments extending in aligned end-to-end abutting relationship in a row along the driving portion of the drive bar, the driving portion being disposed within the insulator segments between the side walls thereof, and a flexible strip of insulating material disposed in interlocking relationship with the opposite side walls of at least a pair of opposite end ones of the insulator segments and extending along the driving portion and shield ing the part of the driving portion exposed between the side walls of the insulator segments.