Next Return Previous

Miller 8174

Version A Version B Version C Version D
Version A Version B Version C Version D

Overview


Version A
(#634)

Front Rear
Front Rear
 
Side Open for Rigging
Side Open for Rigging

Technical Details

I acquired my Miller, Version A from John E. Weinel, Inc. in 1988.

The Miller, Version A is 122 mm. tall, 72 mm. wide, and 89 mm. thick. Mine weighs 803 g.

The Miller, Version A is made from a number of plated steel stampings and minor parts. The rear plate forms a rope channel, and two tabs on the left side are bent and welded to form upper and lower hinge pin channels. The left front plate has a tab bent and welded to form the middle channel. The hinge pin is 9 mm. and piened over at each end, holding it in place. The left side plate is bent forward to support the left sides of the two cam pivots. The right side plate is also bent forward to support the other two cam pivots. The right plate has an upper threaded bushing pressed in from the front, and a subrounded rectangular hole at the bottom. An arm pivots on a hole at the lower right of the rear plate. This pivot has a subrounded rectangular catch that engages the slot. The top of the arm has an 11.6 mm. captive spring-loaded knurled screw that engages the threaded bushing through another hole in the rear plate. A U-shaped channel in the arm captures both the rear and right front plates when closed.

The Miller has two cams. Each cam is made from four steel stampings riveted together. Each stamping has 12 V-shaped notches, forming 13 teeth on each cam. The cams are connected by a stamped channel. The connections and cam axles are all rivets. Springs on the channel pivot pins act to close the cams. A stamped eye with a 25.2 mm. hole pivots from the pin connecting the channel and lower cam. This is the tie-in point.

The right front plate is stamped with "MILLER," FRANKLIN PA.," "8174," "PAT NO 4560029," "UP," an up-pointing arrow, and "SERIAL NO." The number "7810" is hand engraved below the latter stamping. The left front plate is stamped with "UP," an up-pointing arrow, "MFG. DATE," and "09-85." The rear of the arm is stamped "USE ONLY 5/8 IN.16MM DIA.ROPE." There is a sticker inside the rear plate (beside the rope channel) with a red arrow pointing up.

Comments

The Miller rope grab has two type-1 lever cams connected by a bar. This effectively doubles the rope contact area, but also adds quite a bit of weight. Like the Komet Altochut, rope channel swings open for rigging. It is secured by a threaded knob, but the knob is mounted on a lever that actuates two catching dogs at the bottom. This provides some redundancy to the closure mechanism. The Miller is not likely to open accidentally, but it opens easily when desired. To close the Miller, you may need to raise the cam slightly against the spring, but this is easy.

The Miller rope grab is protected by U.S. Patent 4,560,029.


Version B
(#2633)

Front Rear
Front Rear
 
Side Open for Rigging
Side Open for Rigging

Technical Details

I acquired my Miller 8174, Version B in 2017 as part of Bob Thrun's collection.

My Miller 8174, Version B is 71 mm. long, 121 mm. wide, 81 mm. high, and weighs 801 g.

Version B is the same as Version A except that the channel connecting the two cams does not have the stamped ridges; instead, it is stamped with "UP" and a hollow up-pointing arrow.

The right front plate is stamped with "MILLER," FRANKLIN PA.," "8174," "PAT NO 4560029," "UP," an up-pointing arrow, and "SERIAL NO." The number "24797" is hand engraved below the latter stamping. The left front plate is stamped with "UP," an up-pointing arrow, "MFG. DATE," and "05-89." The rear of the arm is stamped "USE ONLY 5/8 OR 3/4 IN.DIA.SYNTHETIC ROPE." There is a sticker inside the rear plate (beside the rope channel) with a red arrow pointing up.

Comments

The changes are cosmetic.

Version C
(#889)

Front Rear
Front Rear
 
Side Open for Rigging
Side Open for Rigging

Technical Details

I acquired Version C on eBay from Lindsay Rissinger in 2008.

The Miller, Version C is 165 mm. tall, 72 mm. wide, and 83 mm. thick. Mine weighs 898 g.

The main difference between Version C and Version A is that Version C has a larger (60 mm. i.d.) attachment eye. This eye is forged, not stamped, and has "4" and "97" in raised letters on one side. The knurled screw is rounded more than the one in Version A.

The markings are similar to those on Version A, with minor differences. The right front plate is stamped with "MILLER," FRANKLIN PA.," "8174," "PAT NO 4560029," "UP," and an up-pointing arrow. The left front plate is stamped with "UP," an up-pointing arrow, "MFG. DATE," and "06-955." The spine of the cam connecting arm is stamped with "UP" and a tall, house-shaped pentagon. There is a sticker inside the pentagon with a red arrow pointing up. The rear of the arm is stamped "MADE IN CANADA" and "USE ONLY 5/8 IN OR 3/4 IN DIA. SYNTHETIC ROPE." There is a sticker inside the rear plate (beside the rope channel) with a red arrow pointing up.

Comments

I like the smaller eye on Version A, but the one on Version C is more rounded, so so it should be easier on lines that are tied directly into the eye.


Version D
(#890)

Front Rear
Front Rear
 
Side Open for Rigging
Side Open for Rigging

Technical Details

I acquired Version D along with Version C.

The Miller, Version C is 167 mm. tall, 67 mm. wide, and 81 mm. thick. Mine weighs 725 g.

Version D is also made from plated steel stampings, but replacing the dull cadmium finish with a shiny alternative. Version D eliminates the side arm present in Versions A and B, and now relies on a captive knurled screw fitted to a slot on the rear plate to hold the rope grab together. The side arm was replaced by a tiny arm with a small channel, held to the right front plate by a small rivet. The cam now has 8 Z-shaped teeth instead of 12 V-shaped teeth. The eye is stamped steel like in Version A, but the i.d. is 61 mm., more like Version C.

The markings are completely different. The right front plate is stamped "Meets OSHA, ANSI A10.14 Z3591, and CSAZ259.2," 6 ft.(1.8m) Max lanyard length," and "CE 0333 EN 353-2. The spine of the cam connecting arm is stamped with "HAUT," "UP," and an up-pointing arrow. The hinge tab on the left front plate is engraved with "DF64 98 51." The rear plate is stamped with "UP," "HAUT," "ALTO," an up-pointing arrow, "MILLER," "model 8174," Read, understand, and follow instructions," "Failure to do so may result in serious injury or death," and "Use only 5/8" (16mm)Dia. synthetic rope," "Maximum capacity 310 lbs (141Kg), and "Made in France." A sticker placed next to the stamped "Dia." reads "OR 3/4 (19mm) Dia." The inside of the rope channel is stamped with "HAUT," "UP," "ALTO," "OBEN," and an up-pointing arrow.

Comments

Version D is lighter than Versions A or B.

I prefer the earlier mechanism for locking the rope grab closed, but there are advantages to each. In Versions A and B, one could close the arm and forget to tighten the screw. The rope grab would work (because of the lower catch and the U-shaped channel), but if the arm opened, so would the rope grab. Since the user would have already be in free fall from whatever they were doing, this would lead to a bad day. On Version D, there is no lower catch, and the little channel on the side arm does not seem substantial enough to hold the device closed, but it is impossible to close the side arm unless the knurled screw is engaged, and it is also impossible to non-destructively unscrew the screw completely without releasing the latch.