Parma

Parma, afzori burrandaest, ki masolehi yaklukhtro surokh va yo surokhi mavjudaro vase mekunad. Navi mamultarini on — Parmai vinti (dar korkardi metall) milaest, ki az qismi burranda, qismi kori va dumcha (raomi 1) iborat ast. Parma tavassuti dumchaash ba patron yo shpin­deli dastgohi parmakuni mahkam karda meshavad. Diametri Parmahoi vintii standart» (D) az 0,25 to 80 millimetr meshavad. Parametrhoi asosii geometrii Parmahoi vinti inhoand:

Rasmi 2. Kunjkhoi parmai vintii me­tallbur.

kunji moilii juyakhoi vinshakl so, kunji nazdi qulla 2f, kunji moilii tegi burrandai bar V, kunji oqib a₍ kunji pesh Baroi tamomi diapazoni diametrhoi Parma qimathoi in parametrho chuninand: oj = 18— —E(G, 2f=80—140°, V = 47—55°, a =

tc.w tit

=8—14°, ley = ^ —(dr — DI-

diametri qismi burrandai Parma dar nuqtae, ki baroi on kunj muayyan karda meshavad. Parma dar yak vaqt dar du harakat — charkhzani va peshravi ishtirok mekunad. Parmaro az pulodi legironidashuda, pulodi tezbur tayyor mekunand yo ba qismi burandai on paykonero az khulahoi sakht meshinonand.