YOKES

They are tools for coupling strain poles to yoke plates, extension links or other support in structures to relieve the mechanical stress of a single or multiple insulator string at anchor or suspension in order to replace damaged insulators.

Yokes and their components are designed to fit various structure configurations. Where models available in this catalog do not meet a specific structure type, tower arm or support bracket and string arrangement drawings must be submitted for evaluation by our engineering department to design the correct yoke and its components.

The yokes are made of heat treated cast aluminum alloy or rolled aluminum plate.

OBSERVATION
Safety click cotter pin (R059738) can be purchased separately as a spare part.

Two-pole strain carrier Yokes

For better user information, in some applications, there are matches between the two versions of cast aluminum and rolled aluminum yokes as follows:

-    RC401-1720 (rolled) is equivalent to RM2946-1 (cast)
RC401-1720 includes steel hook and socket for 7/8” x 1-1/2” extension (RC401-1894).
RM2946-1 includes extension sockets (RM2945-1, RM2945-3, and RM2945-9).

-    RC401-1721 (rolled) is equivalent to RM2946-12 (cast) Both yokes include the RM1942 chain.

-    RC401-0095
It is used with two-pole strain carries and does not require the use of wire grip as it is attached directly to the compression sleeve of the anchor string. Shoes have movable device for the insertion and locking of the clamp before the straining.

Before installation, a proper shoe corresponding to the conductor size to be pulled must be set.

NOTE
The shoe must be coupled over the compression sleeve.
This yoke comes with 04 interchangeable shoes:
- 24 AH for conductors 477 to 556.5 kcmil ACSR Ø 21.7 to 23.4 mm
- 30 AH for conductors 715 to 954 kcmil ACSR Ø 27.4 to 29.6 mm
-     36 AH for conductors 1192.5 to 1351.5 kcmil ACSR Ø 34 to 36.2 mm
- Ø 19.0 to 25.4 mm (3/4” to 1”).

-    RT401-0935 
Designed for hot-end suspension string for triple or quadruple yoke plate coupling, used in conjunction with clevis-clevis tensioner rods.
Constructed with extra strong rolled aluminum sheets.

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Single Pole Strain Carrier Yokes

They are used with the adjustable strain pole (series RC401-2144 through RC401-2149) to release the mechanical strain of double and multiple insulator strings, either in suspension or anchor strings during insulator replacement work.

They are designed to adapt to a number of yoke plates and must be purchased in pairs according to the structure design. In some cases it can be used on either the energized or de-energized side of the insulator string.

For certain applications, some yokes may alternatively be used (see table containing rated working capacity):
-    RC401-1717 can replace RM1947-1
-    RC401-1718 can replace RC401-0003
-    RC401-1719 can replace RC401-0155

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Structure Yokes

	-    RH4783-22 It is a practical and extremely versatile tool for the replacement of insulator strings. It simply and quickly fits onto the structure and supports strain poles in order to relieve the mechanical stress of a suspended insulator string in conjunction with hot-end strain poles and yokes. Yoke supports are designed to fit a number structure configurations. However, we recommend that you submit the structure drawings upon consultation for evaluation by our engineering department. Block-built with aluminum alloy moving parts. It allows a 74 to 181 mm adjustment between the support brackets and measures 554 mm from center to center of the swivel brackets for the strain poles.
	-    RC400-0219 It is generally used in “H” crossarms, with similar design and applications to the steel structure yoke (RH4783-22). To adapt to the various crossarm sizes, the fixing screws can be adjusted in three positions from center to center (230, 280, and 330 mm) and 230 to 305 mm from the vertical.
	-    RC400-0445 It is designed for use at the end of the crossarm, coupled through the RT400-0838 support when necessary. It has its rotary couplings and allows the correct alignment of the strain poles in relation to the yoke on the energized side.  Its rated working capacity is 6804 daN/15000 lb when limited to a 45° angle: 4082 daN/9000 lb.
	-    RT400-0838 It is used in conjunction with the metal crossarm yoke (RC400-0445) when the metal crossarm does not originally have the yoke attachment bracket. Built in aluminum alloy, it is fixed to the metal crossarm through the chain stretcher.
	-    RC401-1722 Constructed of rolled aluminum plate and used in conjunction with strain poles (RC401-2144 to RC401-2149 series), it is normally attached to the hot-end yoke plate of the “V” suspension string. For certain applications, this yoke can be replaced by model RH4794, made of cast aluminum.
	-    RC401-0168 It is used as a single “V” suspension string that can be attached to the yoke plate arm with adjustable strain poles or clevis-eye rings. Made of extra strong rolled aluminum plate.
	-    RT401-0689 Similar to RC401-0168, however, without the bronze adapter. Usually used on the energized side of double-anchored “V” suspension strings, with reduced coupling spaces.
	-    RH4794 It is typically used on the hot-end of single “I” suspension strings on 220 to 345 kV twin-cable transmission lines. Constructed of heat-treated cast aluminum alloy, it has a duplicator saddle (RH4794-1) installed at its base. NOTE The RH4794-2 duplicator support saddle model (which is also used in conjunction with the Jugo RH4794) can be purchased separately when required.
	-    RH4794-1 / RH4794-2 They are used in conjunction with the RH4794 yoke for coupling to the insulator string yoke plate with continuous 360° rotation. They have two sizes (89 and 305 mm) for better fit to the yoke plate and both sizes are made of aluminum alloy.