Handled Type 1 Lever Cam Ascenders

In elementary school science we all learned that a type 1 lever has the fulcrum between the load and the applied force, so it made sense for me to define a Type 1 Lever Cam Ascender as one where the pivot was between the sling and the rope.

Lever cam ascenders generally rely on the mechanical advantage of the lever arrangement to provide sufficient force to keep the cam from slipping. Specifically, the lever acts to provide a higher normal force between the cam face and the standing rope, so the friction generated parallel to the standing rope is sufficient to hold the load. As load is increased, the normal force increases, and so does the parallel frictional force. The cam teeth are secondary in importance to proper lever design, and so lever cam ascenders can often withstand severe tooth wear without losing their ability to hold a load.

The ascenders listed here use the same design, i.e., a hinged frame to connect the lever to the sling rope. I've seen Czech ascenders that have a rigid frame where the sling rope passes through a tube in the handle and ties to the lever, but I haven't been able to obtain any of these for my collection. I believe these were noncommercial, since I didn't seen any of them in any of the Czech Sport shops during my many visits to that country (where the Budvar is excellent, and the Ceské Budéjovice women are gorgeous).

ID	Device	Description	Acquired	Weight	Height	Width	Thickness	Std. volume
219 2106	Black Diamond nForce	LH & RH, stamped pivoting frame, plastic grips, round top & bottom holes, lever cam, Z teeth, hold-open catch	Mountain Gear, 2007 Bob Thrun Collection, 2017	182	194	105	33	663
2959 3564	Camp	RH, stamped pivoting frame, plastic grips, round top & bottom holes, lever cam, sloping & Z teeth, hold-open catch /w removable safety extension	Jasmine Mikulecky, 2020 Vintage Climbing, 2022	258	208	94	42	827
55 2958	Kong-Bonaiti, Version A	LH & RH, stamped pivoting frame, plastic grips, round top & bottom holes, lever cam, Z teeth, hold-open catch	Speleoshoppe, 1982 Jasmine Mikulecky, 20	237	206	94	30	578
56 1556 2107	Kong-Bonaiti, Version B	LH & RH, stamped pivoting frame, plastic grips, round top & bottom holes, lever cam, sloping & Z teeth, hold-open catch /w removable safety extension	Speleoshoppe, 1985 Robert M. Blake, 2011 Bob Thrun Collection, 2017	263	206	95	30	587
58	Leningrad Experimental Shipyard (Ленинградская Экспериментальная Судоверфь ВЦСПС), Version A	LH, stamped pivoting frame, plastic grips, round top & bottom holes, lever cam, sloping & Z teeth, hold-open catch	John E. Weinel, Inc., 1989	275	207	98	29	588
3529	Leningrad Experimental Shipyard (Ленинградская Экспериментальная Судоверфь ВЦСПС), Version B	LH & RH, stamped pivoting frame, plastic grips, round top & bottom holes, lever cam, sloping & Z teeth, hold-open catch	Artyom Babin (Артём Бабин), 2022	259	204	95	28	538
3539	Tashkent Aviation Plant (Ташкентское авиационное производственное объединение имени В.П.Чкалова)	RH, stamped pivoting frame, plastic grips, round top & bottom holes, lever cam, Z teeth, hold-open catch	Artyom Babin (Артём Бабин), 2022	343	223	106	33	775