A mechanical thrombectomy apparatus for removing a clot from a vessel without jamming, the apparatus comprising: an elongate inversion support comprising a catheter (100, 207, 401, 1703, 4005, 4113, 4125, 701) having a distal end (103, 4401) and a distal end opening (105, 707); a tractor (144, 201, 311, 405, 601, 1401, 1600, 4001, 4103, 711) comprising a flexible tube that extends distally in an un-inverted configuration within the catheter (100, 207, 401, 1703, 4005, 4113, 4125, 701), inverts over the distal end opening (105, 707) of the catheter (100, 207, 401, 1703, 4005, 4113, 4125, 701) and extends proximally in an inverted configuration along the distal end (103, 4401) of the catheter (100, 207, 401, 1703, 4005, 4113, 4125, 701), wherein the tractor (144, 201, 311, 405, 601, 1401, 1600, 4001, 4103, 711) comprises a tubular wall, further wherein the tractor (144, 201, 311, 405, 601, 1401, 1600, 4001, 4103, 711) is configured to invert by rolling over the distal end opening (105, 707) of the catheter (100, 207, 401, 1703, 4005, 4113, 4125, 701) when a first end of the tractor (144, 201, 311, 405, 601, 1401, 1600, 4001, 4103, 711) is pulled proximally within the catheter (100, 207, 401, 1703, 4005, 4113, 4125, 701), wherein the tractor (144, 201, 311, 405, 601, 1401, 1600, 4001, 4103, 711) is biased to expand to have an inner diameter that is greater than the outer diameter of the catheter (100, 207, 401, 1703, 4005, 4113, 4125, 701) in the inverted configuration and is biased to expand to have an inner diameter that is greater than the inner diameter of the catheter (100, 207, 401, 1703, 4005, 4113, 4125, 701) in the un-inverted configuration wherein a relaxed outer diameter of the tractor (144, 201, 311, 405, 601, 1401, 1600, 4001, 4103, 711) in the un-inverted configuration is greater than a relaxed outer diameter of the tractor (144, 201, 311, 405, 601, 1401, 1600, 4001, 4103, 711) in the inverted configuration, and wherein the apparatus further comprises an elongate puller (146, 156, 205, 408, 409, 4009, 4105, 712) coupled to the first end of the tractor (144, 201, 311, 405, 601, 1401, 1600, 4001, 4103, 711). an elongate inversion support comprising a catheter (100, 207, 401, 1703, 4005, 4113, 4125, 701) having a distal end (103, 4401) and a distal end opening (105, 707); a tractor (144, 201, 311, 405, 601, 1401, 1600, 4001, 4103, 711) comprising a flexible tube that extends distally in an un-inverted configuration within the catheter (100, 207, 401, 1703, 4005, 4113, 4125, 701), inverts over the distal end opening (105, 707) of the catheter (100, 207, 401, 1703, 4005, 4113, 4125, 701) and extends proximally in an inverted configuration along the distal end (103, 4401) of the catheter (100, 207, 401, 1703, 4005, 4113, 4125, 701), wherein the tractor (144, 201, 311, 405, 601, 1401, 1600, 4001, 4103, 711) comprises a tubular wall, further wherein the tractor (144, 201, 311, 405, 601, 1401, 1600, 4001, 4103, 711) is configured to invert by rolling over the distal end opening (105, 707) of the catheter (100, 207, 401, 1703, 4005, 4113, 4125, 701) when a first end of the tractor (144, 201, 311, 405, 601, 1401, 1600, 4001, 4103, 711) is pulled proximally within the catheter (100, 207, 401, 1703, 4005, 4113, 4125, 701), wherein the tractor (144, 201, 311, 405, 601, 1401, 1600, 4001, 4103, 711) is biased to expand to have an inner diameter that is greater than the outer diameter of the catheter (100, 207, 401, 1703, 4005, 4113, 4125, 701) in the inverted configuration and is biased to expand to have an inner diameter that is greater than the inner diameter of the catheter (100, 207, 401, 1703, 4005, 4113, 4125, 701) in the un-inverted configuration wherein a relaxed outer diameter of the tractor (144, 201, 311, 405, 601, 1401, 1600, 4001, 4103, 711) in the un-inverted configuration is greater than a relaxed outer diameter of the tractor (144, 201, 311, 405, 601, 1401, 1600, 4001, 4103, 711) in the inverted configuration, and wherein the apparatus further comprises an elongate puller (146, 156, 205, 408, 409, 4009, 4105, 712) coupled to the first end of the tractor (144, 201, 311, 405, 601, 1401, 1600, 4001, 4103, 711).