Universal fuse holder and cut-out with built-in safety features and method

• US 5,670,927 A
• Filed: 09/02/1994
• Issued: 09/23/1997
• Est. Priority Date: 09/02/1994
• Status: Expired due to Fees

• Current Assignee: David H. Fritts
• Original Assignee: Robert B. Fennell
• Inventors: Fennell, Robert B.
• Primary Examiner(s): Picard, Leo P.
• Assistant Examiner(s): RYAN, STEPHEN
• Application Number:
  US08/299,622
• Time in Patent Office: 1,117 Days
• Field of Search: 337/171, 337/172, 337/173, 337/174, 337/175, 337/176, 337/177, 337/178
• US Class Current: 337/168
• CPC Class Codes: H01H 31/127 Drop-out fuses

Abstract

A universal fuse holder and cut-out is provided with a slot having a length L and width W aligned with the fuse tube and engageable with the fuse tube and engageable by a projecting arm or member of a hot switch stick so as to enable safe and expedient maintenance and service, particularly in high wind and storm conditions. One contact assembly is lengthwise and rotatably mounted to accommodate long and short fuse tubes and different manufacturer styles of switch assembly.

Claims

1. In a high above-ground distribution fuse cut-out switch system having a pair of spaced contact assemblies supported and spaced by insulator means adapted to be carried on a mounting member, one of said contact assemblies having a pair of laterally aligned trunnion sockets formed therein, an elongated fuse tube assembly having a trunnion contact end with a pair of laterally extending trunnion members receivable in said pair of trunnion sockets, respectively, and a second latching contact end adapted to engage and latch with the second of said contact assemblies when said fuse tube assembly is rotated on said trunnions, the improvement to facilitate safe mounting and demounting of said elongated fuse tube assembly to said pair of spaced contact assemblies from the ground level by a hot/switch stick comprising, said trunnion contact end includes means forming an open ended slot having a width W and wherein said open ended slot has the open end thereof aligned with said elongated fuse tube, said hot/switch stick having an axis and a member projecting laterally of said axis, and an enlargement on the end of said projecting member which is larger than said slot width W, an intermediate portion of said projecting member being narrower than said slot width W such that said projecting member easily slides through said open end into said slot, the weight of said fuse tube and pairs of contact ends and said slot being of a length L such that jiggling and wind forces are insufficient to displace said projection from said slot while said hot/switch stick is being raised to fit said laterally extending trunnion members into said trunnion sockets.

2. The invention defined in claim 1 wherein said open ended slot is such that said lateral projecting member can be rested along the length of said tube and guided along said tube and into said slot to thereby facilitate removal of said trunnion members and fuse assembly from said trunnion sockets.

3. The invention defined in claim 1 or claim 2, including an open sided hook member on said tube adjacent said second latching contact with the open side aligned with said tube so that said projecting member can engage said tube and be easily guided by said tube into engagement with said hook open sided from ground level.

4. The invention defined in claim 1 or claim 2, wherein said trunnion contact end includes a releasable securement means for releasably securing said trunnion contact end to said fuse tube for adjustable rotation of said trunnion contact end around said fuse tube and sliding of said trunnion contact and longitudinally along the length of said fuse tube.

5. A safety attachment for aiding a lineman to mount and demount a fuse cut-out switch using a hot/switch stick having a longitudinal axis and a member projecting laterally of said axis and an enlargement on the end of said member, said fuse having a tubular body and a pair of spaced contact assemblies at the ends thereof, said safety attachment having means forming an open ended slot having a width W and length L, said width W of said slot being smaller than said enlargement, said member having an intermediate portion which is narrower than W, means forming a diverging mouth on said open end of said slot so that the lineman can guide said projection member from movement along said tube into said slot from ground level, said slot having a length L such that, in conjunction with the weight of said fuse cut-out, jiggling and wind and rain forces are insufficient to displace said projection member from said slot while said hot/switch stick is being raised to fit said fuse cut-out to said distribution switch.

6. A method of safely expediting servicing fuse cut-out switches having a trunnion socket contact assembly at one end of an elongated insulator and a latching contact assembly at the opposite end of said insulator and a fuse cut-out having lateral trunnions at one end of a fuse tube and adapted to be received in said trunnion sockets and a latchable contact at the opposite end of said fuse tube and latachable in said latching contact assembly, comprising:

providing an elongated slot on said fuse cut-out adjacent the end of said fuse tube having said lateral trunnions, said slot having a length L and a width W and an open mouth converging to said slot, and a hook switch stick having a laterally projecting member with an enlargement on the end which is larger than said width W,

opening said fuse cut-out switch so that said fuse cut-out is suspended solely by said trunnions in said trunnion sockets,

guiding the laterally projecting member hook switch stick head into said slot by first engaging said tube below said slot by said laterally projecting member and then, while maintaining said laterally projecting member in engagement with said tube, elevating said laterally protecting member into the mouth of said slot and then into said slot and then, while continuing to elevate said projecting member when it engages the base of said slot to thereby elevate said trunnion members out of engagement with said trunnion slots, the length of said slot being such that jiggling and wind forces are insufficient to displace the laterally projecting member from said slot.

7. The method defined in claim 6 including replacing said fuse cut-out in said trunnion sockets by, on the ground, fitting said laterally projecting member in a fuse cut-out having said slot therein and then elevating said fuse cut-out to the height of said fuse cut-out switch to engage said trunnions with said trunnion socket and rotating said fuse cut-out in said trunnion sockets to engage and latch one end of said fuse cut-out in said latchable contacts.