Shaft travel devices such as vertical lift arm devices

Apparatus for moving a load around and along a shaft under a driving force of gas introduced into a cylinder acting in cooperation with an internal piston, comprising:

• said central cylindrical shaft;
• said piston fixed to said shaft at a position intermediate from ends thereof;
• said cylinder surrounding said piston and a portion of said shaft, comprising:
• a hollow extended tube having a first end and a second end and a head at each of said ends, each of said heads having a centrally located aperture therethrough for passage of said shaft;
• first sealing means at each end of said tube to form a gas tight annular chamber within said tube and surrounding said shaft;
• arm support means extending along and connected to an outer side of said tube and being longer than said tube;
• said support means having first and second end portions connected to respective heads of said tube and extending axially therebeyond;
• self-aligning bearing means mounted within said first and second end portions of said arm support means and positioned to be in rotationally and axially movable bearing contact with said shaft;
• and
• non-twisting load transfer means between said end portions of said arm support and said self-aligning bearing means for transferring said load applied to said
• arm through said bearing means to said shaft;
• a gas conduit formed through one head of said inner cylinder for flow of gas under greater than ambient pressure to and from said annular chamber;
• second sealing means mounted circumferentially around said piston and dividing said annular chamber into two axially disposed portions and preventing gas under pressure in one of said portions from passing below to another portion;
• means for venting gas from said chamber;
• and
• a load carrying arm connected to said arm support means;
• such that the force resulting from the mass of an object suspended from said arm is transmitted to said shaft without causing said bearing means to twist from a co-axial alignment with said shaft and said cylinder is capable of traversing both axially along and radially around said shaft to cause said arm support to transfer said load from a first position to a second position.

In a pneumatic cylinder for support of a radially extending load and movement of said load around and along a cylindrical shaft under a driving force of gas introduced into a cylinder acting in cooperation with an internal piston, comprising a hollow extended tube having a first end and a second end and a head at each of said ends, each of said heads having a centrally located aperture therethrough for passage of said shaft;

• sealing means at each end of said tube to form a gas tight annular chamber within said tube and surrounding said shaft;
• and arm support means extending along and connected to an outer side of said tube and being longer than said tube;
• said support means having first and second end portions connected to respective heads of said tube and extending axially therebeyond;
• the improvement which comprises:
• self-aligning bearing means mounted within said first and second end portions of said arm support means and positioned to be in rotationally and axially movable bearing contact with said shaft;
• and
• load transfer means between said end portions of said arm support and said self-aligning bearing means for transferring said load applied to said arm through said bearing means to said shaft without causing said bearing means to twist from a co-axial alignment with said shaft and to prevent transfer of distorting force to said tube;
• whereby said cylinder is capable of traversing both axially along and radially around said shaft to cause said arm support to transfer said load from a first position to a second position.

In an apparatus for moving a load around and along a shaft under a driving force of gas introduced into a cylinder acting in cooperation with an internal piston, comprising a central cylindrical shaft;

• a piston fixed to said shaft at a position intermediate from the ends of thereof;
• a cylinder surrounding said piston and a portion of said shaft, said cylinder comprising a hollow extended tube having a first end and a second end and a head at each of said ends, each of said heads having a centrally located aperture therethrough for passage of said shaft, first sealing means at each end of said tube to form a gas tight annular chamber within said tube and surrounding said shaft;
• and arm support means extending along and connected to an outer side of said tube and being longer than said tube;
• said support means having first and second end portions connected to respective heads of said tube and extending axially therebeyond;
• a gas conduit formed through one head of said inner cylinder for gas flow from an external source into said annular chamber;
• second sealing means mounted circumferentially around said piston and dividing said annular chamber into two axially disposed portions and preventing gas under pressure in one of said portions from passing below to the other portion;
• means for venting gas from said chamber;
• and a load carrying arm connected to said arm support means:
• the improvement which comprises:
• self-aligning bearing means mounted within said first and second end portions of said arm support means and positioned to be in rotationally and axially movable bearing contact with said shaft;
• and
• non-twisting load transfer means between said end portions of said arm support and said self-aligning bearing means for transferring said load applied to said arm through said bearing means to said shaft;
• such that the force resulting from the mass of an object suspended from said arm is transmitted to said shaft without causing said bearing means to twist from a co-axial alignment with said shaft.