US2175328A - Disconnecting device - Google Patents

Description

Oct. 10, 1939. c, WALSH 2,175,328

DISCONNECTING DEVICE Filed March 21, 1952 2 Sheets-Sheet 1 INVENTOR Oct. 10, 1939. c. H. WALSH 2,175,328

DISCONNECTING DEVICE Filed March 21, 1932 2 Sheets-Sheet 2 J1 N 1 f WMZ/ZAZ INVENTOR Patented Oct. 10, 1939 UNITED STATES PATENT OFFICE DISCONNECTING DEVICE Carroll H. Walsh, Pine Blufl, Ark.

Application March 21, 1932, Serial No. 600,245

17 Claims.

This invention relates generally to protective devices and more particularly to fuse-containing disconnecting devices for use in connection with electric transmission and distribution lines and has for its principal object, the provision of means for positively disconnecting a circuit whenever the current therein exceeds a definite predetermined magnitude.

Another object of this invention is the provision of means for removing the fuse-containing element from the circuit following the interruption of the current therein.

Another object resides in the provision of means for manually causing normal load current to destroy the fuse within the fuse-containing element.

A further object of this invention is to provide a simple, inexpensive and effective disconnecting device for the purpose above described.

With the above and other objects in view which will appear from the description, my invention resides in a novel construction, combination and arrangement of parts as hereinafter described and more particularly. defined by the appended claims, it being understood that such changes as come within the scope of the claims may be made in the embodiment herein disclosed.

In the drawings,

Figure 1 is a side elevational view of the device in the service position;

Figure 2 is a front elevational view of the fuse, part 33 having been removed;

Figure 3 is a side elevational view of the fuse: and,

Figure 4 is a fragmentary side elevational view of the upper contact shown in section.

Figure 5 is a rear elevational view of the lower contact.

Referring now more in detail to the drawings, Figure 1 shows the device mounted in the service position on some suitable support as crossarm l2, by means of the U bolt II and the U shaped metal member Ill. The upper contact support I! and the upper insulator l3 are assembled on the upper arm of the U-shaped support III in any suitable manner, as by means of the cap screws l6, and in a similar manner the lower clip support l8 and the lower insulator H are assembled on the lower arm of the U-shaped support l9 by the cap screws IS. The upper resilient contact clip 28 is secured to the upper contact support H by the bolt 51, the latter passing through and thus securing the flat T-shaped metal member 30. The hook 29 and the metal member 30 thus form a latch for fastening the-fuse tube assembly in the service position in the upper contact clip. An extension of the metal member 30, together with the terminal bolt 22 provides means for attaching a line wire I 9 thereto.

The lower resilient contact clip 25 is attached 5 to the lower contact support l3 by means of the bolt 2|, the latter also providing means for attaching a load wire thereto.

Referring now to Figs. 2, 3', 4, and 5, I will now explain the construction of the fuse tube assembly. Since this fuse is preferably of the expulsion type, the fuse tube 23 may be a stout insulating tube of indurated fiber or other stout insulating material. The upper end of tube 23 is threaded to receive the metal cap 31, into which 15 is screwed a somewhat smaller metal tube 49 for providing a passage for the fuse wire through the top assembly. The resilient metal strips 33 are rigidly attached to the metal cap 31 in any suitable manner, as by brazing. or soldering, and ex- 20 tend to and support the upper terminal 54 of the fuse. The knurled cap 35 is adapted to screw on upper terminal 54 by means of cooperating threads on these parts.

A pair of U-shaped metal members 39 are rig- 25 idly attached to the resilient strips 36 in any suitable manner, not shown, as by riveting or brazing, and are adapted for lateral movement. The movable metal member 55 is adapted for reciprocatory movement within the opening formed by the pair of U-shaped metal members 39, and

is guided in its reciprocations by the said U- shaped members and the pair of resilient strips 36.

A pair of cylindrical arms 34 extend outwardly 35 from the opposing sides of the movable member 55, and cooperate with the sloping portions of the U-shaped members 33 in such a manner that a downward movement of the movable member 55 causes the U-shaped members 39 to move lat- 40 erally away from each other against the bias of the resilient strips 33. The top of the movable member 55 is provided with a small opening to provide a passage for the fusible element 39 therethrough, and is in addition biased in an upward direction by the coil spring 48.

The pair of cylindrical arms 34 extending outwardly toward the front of the fuse assembly are drilled and tapped to receive the screws 53, and in this way L-shaped member 33 is secured to the movable member 55.

The drawings show the top contact in the collapsed position. It is apparent that any fo'rce urging the L-shaped member in a downward direction will deform the coil spring l8, and at 55 the same time cause the [Ll-shaped contact members 39 to move laterally away from each other by the action of the cylindrical arms 34 against the sloping portions of the U-shaped contact members.

The pair of cylindrical arms 34 extending outwardly toward the rear of the fuse assembly are also drilled and tapped to receive the screws 53, for attaching the T-shaped member 32 to the movable member 55. The U-shaped hook 29 is urged in an upward or unlatching direction by the top of the T-shaped member 32 contacting therewith when the upper contact is in the collapsed position shown.

The lower contact 24 of the fuse assembly comprises a flat metal sheet having upturned sides to form contact surfaces for engagement with the stationary contact 25. A pair of ears having holes therethrough together with the laterally extending pins 44 provide a hinged connection with the fuse tube. The flexible conducting braid 42, connecting the lower contact 24 and the lower end of the fuse tube 40 prevent the passage of current through the hinged connection. The entire fuse tube assembly is thus free to rotate on the pins 44 without any movement of the lower contact 24.

The metal block 40 has a hole providing for the passage of the fuse tube 23, and is rigidly mounted thereon, as by the extension of the cap screw 43 to form a set screw. The metal stud M is screwed into a cooperating threaded opening in the block 48, and is further provided with a slot to receive the fuse wire. A cap 25 is adapted for screwing on metal stud 4! to provide an electrically and mechanically secure joint with the fusible element 38.

The fusible element 38 is preferably provided with the buttons 50 and 55' adjacent the upper end thereof and the button 56 adjacent the lower end thereof.

To install the fusible element in the fuse tube, the cap 35 is removed from the top of the tube assembly, and the cap 26 from the slotted stud bolt 4|. The lower end of the fuse including the button 56 is inserted first in tube from the top. When the lower end of the fuse wire appears at the bottom of the tube, the L-shaped member 33 is placed against some solid object, and force applied in a direction to move the L- shaped member 33 toward the bottom of the fuse tube assembly until the lower button 56 can be properly seated in the slotted recess provided in stud bolt 4|. Caps 35 and 26 are then replaced in their original positions.

It will be apparent that such a movement of the L-shaped member 33 will laterally expand the upper contact members 39, permit the hook 29 to fall to the engaging position and deform the spring 48.

A switch hook of the usual type is then inserted through the opening 46 in the lower contact 24, and the fuse assembly placed in the lower hooks 21. The fuse assembly is then rotated on the pins 44 from the dotted position shown in Fig. 1 to the position indicated by the continuous lines, at which position the assembly is latched in the service position by the action of hook 29 engaging the upperT-shaped member 30.

With the fuse in the service position as shown in Fig. 1, the current entering the upper terminal 22 will pass through metal member 30 to the upper contact clip 28, thence through the fusible element 33 in the tube 23 to the metallic block 48, thence through the flexible conductor 42, the

lower removable contact 24 and the fixed resilient contact 25 to the lower terminal M.

It is now possible to remove the fuse assembly from the service position without destroying the fusible element or to manually break the fusible element within its container.

To remove the fuse assembly from the service position, it is only necessary to insert a switch hook of the ordinary type in the eye 3!, and urge the eye M in a downward direction. This movement disengages the hook 29 from the T-shaped member 30, and permits the fuse assembly to be urged to the open position shown by the dotted lines in Fig. 1.

In many cases in practice, the normal load current through a fuse is so large that it is difficult to break the ensuing arc when the device is operated in a manner similar to a disconnect switch. Under such conditions, the circuit-interrupting are due to the load current may be interrupted inside the fuse tube by urging the L- shaped member 33 in an upward direction. This movement will break the fuse wire inside the fuse-containing tube, and the arc is thus quickly and safely extinguished.

Upon the occurrence of a current sufficient to melt the fusible element, the fuse assembly unlatches and drops to the open position shown by the dotted lines in Fig. 1. This will be apparent from the construction above disclosed, since the movable member 55, biased by the spring 48 will, upon the melting of the fusible element 38, move upward to permit the collapse of the upper con- .tacts 39 under the biasing of the resilient strips 35, and at the same time raise the latch 29 to disengagement with the T-shaped member 30 through the movement of the T-shaped member 32. In this manner, upon the occurrence of an overcurrent, the fuse tube assembly is released, and rotates by gravity on the pins 44 to the open position shown by the dotted lines in Fig. 1.

It will be seen that the gases within the fuse tube 23 due to the circuit-interrupting are expand in a direction to aid the movement of the movable metal member 55 in a direction to unlatch and release the fuse tube assembly from thetop stationary contact 28.

The invention here disclosed requires no changes in many types of commercial fuse tube mountings, since all essential parts are mounted upon the fuse tube rather than on the stationary contacts assembled on the insulators. For this reason my removable fuse tube structure may be used to replace the existing fuse tubes lacking the advantages of this invention by simply removing the older type of fuse tubes and inserting in the same mounting a tube assembly of the type here disclosed.

From the foregoing description taken in connection with the accompanying drawings, it will be apparent to those skilled in the art that I provide a novel and improved discharge device for the purpose described.

What I claim as my invention is:

1. In a fuse-containing disconnecting device having an expandible contact mounted on a fuse-containing element of insulating material, a yieldable contact clip engageable by the contact when the latter is expanded, means including a fuse wire under tension adapted to expand the said contact for engagement with said yieldable cooperating contact, the contact automatically collapsing and disengaging the clip when the fuse wire breaks.

2. A disconnecting device having, in combination, a fuse-containing element of insulating material adapted to be interposed between a line and a load, a yieldable latch mounted on said fusecontaining element, means including a fusible wire under tension for latching the said fusecontaining element in a fixed yieldable cooperating contact, whereby the parting of said fusible wire unlatches the said fuse-containing element, and means including a spring and an eye on said latch, whereby the said fuse-containing element may be manually removed from the said cooperating contact Without breaking the said fusible wire.

3. A disconnecting device having, in combination, a fuse containing tube of insulating material having an upper contact and a lower contact for cooperating with resilient stationary contacts, the lower contact being removably hinged to the said tube, whereby the said tube may rotate about the said hinge without causing movement of the said lower contact from the stationary cooperating contact.

4. In a fused disconnecting cartridge, an expandible contact mounted on a fuse-containing member, a clip engageable by the contact when the latter is expanded, and means including a fusible wire under tension for normally preventing the collapse of said contact, the contact being automatically collapsible to release from the clip when said wire fuses.

5. A disconnecting device having in combination a tube of insulating material containing a fusible element and contacts adjacent to each end of the said tube adapted for cooperating with resilient stationary contacts, the said fusible element having buttons adjacent each end thereof for cooperating with stops mounted upon the said tube and means including an expandible contact and a latch adjacent one end of the said tube whereby a definite distance between buttons on the said fusible element is required to latch the said tube in engagement with the said stationary contacts.

6. A disconnecting device having, in combination, a collapsible contact mounted on a fuse tube of insulating material and operable by a spring and a movable member biased by the said spring, a member rigidly fixed on the said movable member and a fuse wire under tension attached to and restraining the movement of the said movable member whereby the said fuse wire may be broken by manually urging the said member in a direction to increase the tension of the said fuse wire.

7. A fuse switch comprising contact clips, a cartridge, contacts on tga cartridge, one of the contacts on the cartridge engaging one of said clips, the other of said contacts on the cartridge being expansible to grip the other clip and collapsible to release therefrom, a tensioned fuse associated with the cartridge and means whereby the tension of the fuse is adapted to maintain the expansible contact in holding position in its clip until the fuse is untensioned, as when it is blown.

8. A fuse switch comprising contact clips, a cartridge, contacts on the cartridge, one of the contacts on the cartridge engaging one of said clips, the other of said contacts on the cartridge being expansible to grip the other clip and collapsible to release therefrom, a tensioned fuse associated with the cartridge, means whereby the tension of the fuse is adapted to maintain the expansible contact in holding position in its clip until the fuse is untensioned, as when it is blown, and means including a slidable member mounted on said cartridge and attached to said fuse for manually breaking the fuse to accomplish said functions.

9. A fuse switch comprising contact clips, a cartridge, contacts on the cartridge, one of said contacts engaging a contact clip, spring latching means for holding the other contact in its clip,

means under control of a tensioned fuse in the cartridge normally expanding the last-named contact to frictionally engage its clip, means effecting a collapse of said contact to free it from its clip and a release of said latch upon blowing of the fuse, and means for manually breaking the fuse to effect said functions.

10. A disconnecting device comprising a base, spaced stationary contacts insulatingly mounted on said base, a fuse tube assembly normally spanning said base contacts, said assembly including an insulating tube having a contact at each end and a fusible element connected between said contacts disposed within said tube, one of said tube contacts being pivotally mounted with respect to said tube, said tube contacts cooperating with said base contacts and being retained in cooperating position thereby, and means for releasing said other tube contact and pivotally moving said fuse tube assembly with respect to said one tube contact whereby said fuse tube is moved to an open position without relative movement of the one tube contact and its retaining base contact.

11. The structure of claim 10 wherein said releasing means is controlled by the tension in said fusible element to maintain said other tube contact in its retained position in the unfused condition of said element and upon fusing of said element, said contacts are released from each other.

12. In a fused disconnecting device, spaced insulated upper and lower contacts, a fuse tube movable between open and closed positions, means including a fusible element within said tube electrically connecting said contacts, relatively movable inner and outer nested members mounted on said fuse tube, said nested members cooperating with said fusible element to maintain said fuse tube in the closed position when said fusible element is unfused, and means responsive to a relative longitudinal movement of said nested members for actuating said fuse tube to the open position when said fusible element is ruptured.

13. In a fused disconnecting device, spaced insulated upper and lower contacts, a fuse tube movable b'etween open and closed positions, means including a fusible element within said tube electrically connecting said contacts, a pair of coaxially related hollow members associated with said fuse tube, one member being rigidly secured to said tube and the other member being slidably movable with respect to said one member, means for fastening said fusible element to said slidably movable member, resilient means for tensioning said fusible element, means dependent upon tension in said fusible element for holding said fuse tube in the closed position, and means responsive to a longitudinal coaxial movement of one of said hollow members with respect to the other for releasing said fuse tube.

14. In a fused disconnecting device having an open and a closed position, spaced insulated upper and lower,contacts,,a fuse tube spanning said contacts, said fuse tube being pivotally mounted at its lower end for swingable movement between the open and closed positions, a fusible element extending through said tube and electrically connecting said contcats when said fuse tube is in the closed position, a metal member mov= able endwise with respect to said tube mounted thereon, an upper fuse tube contact cooperating with said movable member and arranged to frictionally engage the upper contact, latch means for said fuse tube controlled by said movable member for maintaining the engagement, means for fastening said fusible element to said movable member whereby to restrain movement thereof, and resilient means urging said movable member to unlatch said fuse tube, whereby upon fusing of said fusible element said fuse tube is unlatched, said upper fuse contact is disengaged from said upper contact, and the fastened portion of said fusible element is moved away from said tube along the axis thereof.

15. A disconnecting and removable assembly for cooperation with a pair of spaced contacts comprising an insulating tube having a contact at each end thereof, a fusible element within said tube bridging said tube contacts, one of said araaaae contacts being rigid on said tube and the other being pivotally mounted on said tube whereby said assembly may be removed from said spaced contacts entirely or may be swung away from one contact only. a

16. In a fused disconnecting device, the com bination of a base, contacts on said base, a fuse tube disposed between said contacts and including a fusible element therein bridging said contacts, and manual means for breaking said element within said tube.

17. In a fused disconnecting device, the combination of a base, contacts on said base, a fuse tube disposed between said contacts and including a fusible element therein bridging said contacts, means tending to move said tube out of contact bridging relation, means controlled by the tension of said element for disabling said first named means, and manual means for breaking said element and permit said first named means to operate.

GARRDLL H. WALSH.

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