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US 4,132,041 AGranted
Telescopic apparatus
OwnerBernardus C. Van den Broekinventor
Life of this patent
Estimating the term…
Abstract
A telescopic boom assembly including first and second telescoping members. The assembly employs rack and pinion telescoping mechanisms which are driven by hydraulically controlled piston and cylinder members. The combination provides positive and precise positioning of the telescoping members and extremely smooth movement thereof.
Claims6
A telescopic boom assembly including a first boom member,
- a second boom member telescoping within said first boom member,
- said boom assembly having a retracted position wth said second boom member telescoped within said first boom member and an extended position with said second boom member extended from said first boom member,
- a first rack fixed onto said first boom member adjacent one end thereof and extending toward the middle thereof,
- a second rack fixed onto said second boom member,
- the beginning of said second rack being adjacent to the end of said first rack when said second boom member is in the retracted position,
- a first cylinder fixed into said first boom member,
- a piston within the cylinder,
- a piston rod attached to the piston and extending from the cylinder,
- a rotatable pinion wheel attached to the piston rod, and
- said rotatable pinion wheel meshing with both said first and second racks and said first and second racks being positioned so that when said piston rod is moved from a retracted to an extended position, said pinion wheel moves along said first rack and forces said second rack outward to cause said second boom member to move to the extended position.
7 more elements
Dependencies are inferred from the claim text.