Front	Rear

Side	Open for Rigging

Technical Details

I acquired my Doug Phillips pulley from John Middendorf in 2019.

This pulley is 68 mm. long, 121 mm. wide, 44 mm. high, and weighs 240 g.

The Doug Phillips pulley consists of a pulley sheave and a spring-loaded eccentric cam between two 3.1 mm. aluminum alloy side plates. The sheave is 55.4 mm. in diameter and 18.2 mm. thick, with a 13.7 mm. wide, 4.4 mm. deep U-shaped rope groove. The sheave axle is a 5/16-18 UNC hex-socket cap bolt that is secured to the fixed side plate with a nylon lock nut.

The cam has 15 sub triangular grooves forming sixteen subtriangular teeth. The cam is mounted on a 5/16-18 UNC hex-socket cap bolt that is secured to the fixed side plate with a nylon lock nut. There are two copper alloy spacers on the bolt. A 0.6 mm. wire spring sits in a slot in the cam, where it wraps three times around the cam axle and is secured to a 10-32 machine screw by two hex nuts. A third hex nut secures the screw to the fixed side plate.

The free side plate is stamped with "JOHN" and "MIDDENDORF."

Comments

John provided the following information:

That pulley was made by Doug Phillips at Metolius, who made about 10 and asked me to sell them for him when I was living in Yosemite. This was about 1985.

Werner stamped my name on it.

The pulley did not work well, as the cam against the pulley wheel system allowed slippage with high loads.

It helped me to design the wall hauler, as I realised the cam needed to grab the rope separately from the wheel. I also got inspiration for the wall hauler from the makeshift Clog handled ascender/SMC 2.5” pulley combination which had been crafted by a few ingenious wall climbers at that time.

John Middendorf