Next Return Previous

Reflex

Front Rear
Front Rear
 
Open for Rigging
Open for Rigging

Technical Details

I acquired my Reflex from Konstantin Serafimov in 2007.

My Reflex is 137 mm. tall, 86 mm. wide, and 30 mm. thick, and weighs 278 g. The shell is made from 1.9 mm. stainless steel, and consists of two assemblies hinged together to form, when closed, a square-based rope channel. The piece forming the rear and right side of the channel is 41 mm. wide and 68 mm. high, with an additional 68 mm. extension welded to its base. The cam axle is permanently attached the upper section, and a small stop pin prevents over-opening the cam. The left side plate swings open on a hinge. A hole allows the left side plate to close over the cam axle. A pair of spring-loaded levers held under a screwed-on cover plate operate in scissors-fashion to engage a groove in the cam axle.

The cam is cut from a piece of 12 mm. stainless steel. The cam has a flat face that pivots on a 6 mm. pin set in the cam toe. The cam face is 36 mm. high, and is flat except for the top and bottom 3 mm. which are each well-rounded. A 72 mm. length of 6 mm. rod is welded to the base of the cam.

The only markings on this Reflex is a large "2" stamped in the cam.

Comments

Konstantin Serafimov invented the Reflex after surviving an out-of-control "grabbed ascender" incident. After seeing the Levistan, Version B ascender on my web site, he had a friend of his make this Reflex for me. As he said,

I sure you already understand - "Reflex" is universal cable/rope self-belay ascender. And principle of it's operation founded on applying "panic-reflex," when the victim instinctively grabbed the ascender.

As I wrote, I think up principle "reflex self-belay ascender" after my descent with grabbed "gibbs" in the cave Kutuk-Soumgan in 1980 and series tests like Don Davison's and Dan Meier's three-rope rig, in 1981-82.

Since 1983 many my friends, cavers of my club "Soumgan" and other soviet caving clubs made and used different ascenders of "positive reflex-action" - as "Leviston-B," and I don't now accidents with this devices, never a one.

Konstantin's approach to rappel safety differs from mine, but I think his is practical, provided one always grabs below the ascender.

Konstantin sent me some pictures showing his Reflex ascender from 1983, which I edited slightly. There are five views:

  1. Reflex made from a Soviet version of the Gibbs.
  2. Konstantin's Reflex, showing the "positive reflex action" engaged by grabbing the lower portion of the ascender
  3. Open. See how the cam axle is turned to provide for quickly closing and latching the side plate.
  4. The Reflex on rope.
  5. The Reflex, open to show the internals.

The flat cam face will allow the Reflex to slip under shock loads, but it seems to be adequate for normal loads. The extensions that provide "positive reflex action" considerably and unfortunately increase the ascender's size. The latch mechanism is clever. Mine has some rough edges that make opening the ascender a bit awkward, but closing is quite smooth. Unfortunately, the fine mechanism is subject to jamming in dirty conditions, especially in sandy mud.

The Levistan, Version B was almost certainly a copy of the Reflex. Konstantin published his concept in the Moscow journal Tourist in 1986.

Konstantin has some additional information on his web site, including, with my permission, a Russian translation of my Rappel Safeties Internet Post.