In　this　study,　the　so-called　quasi-spiral　motion　pattern　of　a　particular　3R　(revolute)　chain,　which　could　track　a　quasi-spiral　curve,　is　discovered　for　application　in　enveloping　gripping.　Naturally,　a　novel　perspective　on　the　synthesis　of　1-DOF　(degree　of　freedom)　single-loop　6R　and　7R　mechanisms　is　presented　to　implement　the　quasi-spiral　motion　pattern.　In　these　processes,　the　method　of　factorization　of　the　motion　polynomials　is　used　to　synthesize　a　series　of　single-loop　mechanisms　with　the　motion　to　generate　quasi-spiral　curves.　By　employing　the　proposed　method,　numerous　innovative　6R　and　7R　mechanisms　have　been　developed　to　construct　dual　layers　of　grippers　based　on　specific　network　regulations.　Taking　a　novel　6R　mechanism　as　an　example,　the　forward　solution　of　the　mechanism　is　determined,　and　the　relationship　between　different　rotation　angles　is　obtained.　Then,　the　changes　in　each　angle　are　displayed.　Finally,　the　novel　6R　and　7R　mechanisms　are　employed　as　units　to　determine　the　networking　method　and　assemble　new　types　of　grippers.　Grippers　formed　by　the　aforementioned　1-DOF　mechanisms　exhibit　the　characteristics　of　enveloping　grasping.　Copyright　©　2024　by　ASME.