the upper end 102 of the tubular mandrel 100 may be adapted to accept a standard wireline running and pulling tool and or may also be adapted to accept the packer 14 as described below when the downhole anchor 12 is run into the well it is indexed to the running position r where the pin 124 bears upwards against the j slot sub 104 as a consequence of the drag created by the belly springs 112 as the downhole anchor 12 is moved downhole as shown in fig6 the slips 118 are partially retracted in the running position r but do not interfere with the tubing t once in position the tool string which may include hydraulic jars spang or mechanical jars and a weight bar is raised to take up slack in the tool string and index the downhole anchor 12 to the pre set position ps as may be seen simply pulling up on the tool string will cause the pin 124 to move within the slot from the running position r to the pre set position ps lowering the tool string from the pre set position ps will cause the pin 124 to move to the set position s which actuates the slips 118 to engage the tubing interior surface fig7 shows the slips 118 at a maximum set position the slips 118 may engage the tubing t before the slips 118 reach the maximum set position at this point the downhole anchor 12 should accept and hold the weight of the tool string if not this may indicate that the downhole anchor 12 is placed in an unsuitable place in the tubing t.