Multiple locking position safety leg for lifts
A lift with a multiple locking position safety leg includes a lift bed for engaging in objects to be lifted together with a fluid cylinder to be connected to the lift bed and extendable and retractable to move the lift bed between two extreme positions including a fully lowered position and a fully raised position. A latching mechanism is provided for holding the lift bed in any of a plurality of positions between the extreme positions and includes a plurality of vertically spaced latches operated by gravity to move to latching positions, one for each of the plurality of positions, and a single actuator for simultaneously moving and holding each of the latches against gravity from the latching positions to allow the lift bed to be moved to the fully lowered position. Also disclosed is a kit for retrofitting existing lifts with the safety leg.
1. A kit for retrofitting an in ground lift having an antirotation tube with a load holding device, comprising:
an elongated, cylindrical tube;
a nut connected to said tube at one end thereof;
a plurality of first slots spaced at predetermined locations in one side of said tube;
a plurality of second slots spaced generally in alignment with corresponding ones of said first slots and located on a side of said tube opposite said one side;
an additional slot in said opposite side and between said nut on the one hand and said second slots on the other hand;
a plurality of elongated dogs each having a length greater than said outside diameter, one for each aligned pair of said first and second slots;
a plurality of pivot pins, one for each dog, within the interior of said tube and each journaling an associated dog for rotation about an axis mutually transverse to said tube and a corresponding one of said aligned pairs of slots between a first position wholly within said tube and a second position wherein opposite ends of said dogs extend out of both the first and second slots of the associated pair, said axis and/or said dogs further being such that each dog has more mass between said axis and one end of the dog than the other end;
a manual actuator pivoted within said tube and movable between a first position within said tube and a second position extending exteriorly of said tube and
a linkage connecting said actuator and each of said dogs and movable in response to movement of said actuator to said actuator second position to allow movement of said dogs from said dog second positions toward said dog first positions, and responsive to movement of said actuator toward said actuator first position to allow said dogs to move toward said dog second positions.
2. The kit of claim 1 wherein said linkage includes an elongated rigid link mounted for reciprocal movement within said tube, and a plurality of cams spaced along the length of said link at positions whereat they may be brought into engagement with a corresponding one of said dogs to one side of the corresponding axis.
3. The kit of claim 2 wherein said link and said cams are located so as to engage each said dog between its axis and its said other end to positively move each said dog toward said dog first positions while allowing each dog to be biased toward said dog second position by gravity.
4. The kit of claim 3 wherein said actuator is connected to said link by a lost motion connection.
5. The kit of claim 2 wherein said actuator is connected to said link by a lost motion connection.
6. A kit for retrofitting an in ground lift having an antirotation tube with a load holding device, comprising:
an elongated, cylindrical tube;
a plurality of first slots spaced at predetermined locations in one side of said tube;
a plurality of second slots spaced generally in alignment with corresponding ones of said first slots and located on a side of said tube opposite said one side;
a plurality of elongated dogs each having a length greater than said outside diameter, one for each aligned pair of said first and second slots;
a plurality of pivot pins, one for each dog, within the interior of said tube and each journaling an associated dog for rotation about an axis mutually transverse to said tube and a corresponding one of said aligned pairs of slots between a first position wholly within said tube and a second position wherein opposite ends of said dogs extend out of both the first and second slots of the associated pair, said axis and/or said dogs further being such that each dog has more mass between said axis and one end of the dog than the other end;
a manual actuator pivoted within said tube and movable between a first position within said tube and a second position extending exteriorly of said tube and
a linkage connecting said actuator and each of said dogs and movable in response to movement of said actuator to said actuator second position to allow movement of said dogs from said dog second positions toward said dog first positions, and responsive to movement of said actuator toward said actuator first position to allow said dogs to move toward said dog second positions.
7. The kit of claim 6 wherein said linkage includes an elongated rigid link mounted for reciprocal movement within said tube, and a plurality of cams spaced along the length of said link at positions whereat they may be brought into engagement with a corresponding one of said dogs to one side of the corresponding axis.
8. The kit of claim 7 wherein said link and said cams are located so as to engage each said dog between its axis and its said other end to positively move each said dog toward said dog first positions while allowing each dog to be biased toward said dog second position by gravity.
9. The kit of claim 8 wherein said actuator is connected to said link by a lost motion connection.
10. The kit of claim 7 wherein said actuator is connected to said link by a lost motion connection.