1. A drum comprising a shell, said shell provided with a combining member, a counterhoop provided with an engaging member to combine with said combining member, a head sandwiched between said shell and said counterhoop.
2. The drum as claimed in claim 1, wherein said shell is provided with a frame, and said frame is provided with a combining member.
3. The drum as claimed in claim 2, wherein said shell and said counterhoop both are provided with plural threaded holes to correspond to one another for screws to engage with for combining said shell tightly with said counterhoop.
4. The drum as claimed in claim 1, wherein said combining member and said engaging member are threads.
5. The drum as claimed in claim 1, wherein said head is provided with a head collar fixed around its outer circumference, and said head collar is sandwiched between said shell and said counterhoop.
6. The drum as claimed in claim 1, wherein said counterhoop is provided with a folded member extending inward from an upper end to compress said head.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of protecting a switch having exposed conducting components and being mounted on a structural frame that forms part of an electrical power transmission system, the switch having one or more insulators extended from the structural frame, first and second conductor connectors supported on the one or more insulators, and a blade connected to pivot to close and open an electrical path between the first and second conductor connectors, the method comprising mounting a barrier wall adjacent the switch and on the structural frame.
2. The method of claim 1 in which the barrier wall is spaced from the switch when mounted.
3. The method of claim 1 in which the switch is a knife blade switch and the blade comprises one or more throw arms.
4. The method of claim 1 in which the switch has lateral sides defined as being extended from the structural frame and between the first and second conductor connectors, in which the barrier wall is positioned along one of the lateral sides when mounted.
5. The method of claim 1 in which the switch has two or more insulators whose respective axes define a plane extended from the structural frame, in which the barrier wall is mounted parallel to the plane.
6. The method of claim 1 in which the blade is connected to pivot in a lever plane, and in which the barrier wall is mounted parallel to the lever plane.
7. The method of claim 1 in which the barrier wall has a plurality of wind apertures.
8. The method of claim 1 in which the barrier wall is mounted to the structural frame using one or more fasteners.
9. The method of claim 1 in which the structural frame comprises one or more beams connected to a switch base, which supports the one or more insulators.
10. The method of claim 1 in which the barrier wall comprises a base mounted to the structural frame.
11. The method of claim 10 in which the barrier wall comprises a cantilever barrier extended from one side of the base.
12. The method of claim 1 in which the switch is one of a set of adjacent switches on the structural frame, and in which mounting comprises mounting the barrier wall between the adjacent switches.
13. The method of claim 12 in which the set of adjacent switches is part of a polyphase electrical power transmission system, each of the adjacent conductors being arranged to receive a respective phase of the polyphase electrical power transmission system.
14. The method of claim 12 further comprising a gang actuator rod connected to each switch of the set of adjacent switches, in which the barrier wall comprises a passage for the gang actuator rod.
15. The method of claim 12 in which the barrier bisects a space between the adjacent switches.
16. The method of claim 1 in which the barrier wall comprises dielectric material.
17. A method of protecting a set of adjacent conductors on a structural frame that forms part of a polyphase electrical power transmission system, each of the adjacent conductors being supported on the structural frame by one or more insulators, each of the adjacent conductors being arranged to receive a respective phase of the polyphase electrical power transmission system, the method comprising mounting a barrier wall on the structural frame and between two of the adjacent conductors.
18. The method of claim 17 in which the set of adjacent conductors comprise a set of adjacent switches.
19. A method comprising mounting a barrier wall to a structural frame that forms part of an electrical power transmission system, the barrier wall having:
a base mounted to the structural frame; and
a cantilever barrier extended from one side of the base and directed away from the structural frame.
20. The method of claim 19 in which the barrier wall is mounted adjacent a switch.