US3667347A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stroke control device for hydraulic cylinders
Assignee: Prince Manufacturing Corp
•
Filing: 1970-05-22
•
Granted: 1972-06-06
•
Expires: 1990-05-22
Abstract
Abstract A hydraulic cylinder including a piston rod extending from one end and having adjustable actuating member thereon for engaging the piston rod of a control cylinder in communication with the hydraulic cylinder such that oil is circulated from the hydraulic cylinder through the control cylinder and is shut off upon the actuating element moving the control cylinder piston rod to a closed position thereby limiting further movement of hydraulic oil within the hydraulic cylinder. A double or single acting hydraulic cylinder may be employed and upon fluid flowing in a reverse direction the control cylinder piston will be extended opening the conduit from the hydraulic cylinder through the control cylinder unit for oil circulation. The piston in the control cylinder is entirely metallic and engages an elastomeric seat seal only after the oil pressure has substantially dropped due to the inlet opening into the cylinder having been closed off by the control cylinder piston moving across the inlet opening. The control cylinder may be externally mounted on the hydraulic cylinder.
Inventors
- 👤 Donald A Patrick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:51
CPC Classifications
F; F15; F15B; F15B15/00; F15B15/20; F15B15/24
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
368 words
In combination, a hydraulic cylinder having a first housing defining a first chamber with a first piston movable thereon with a first piston rod extending through one end of said housing, a first conduit in communication with said first chamber on one side of said first piston, a second conduit in communication with said first chamber on the opposite side of said first piston, a stroke control unit comprising a second housing operatively secured to said housing and having a second chamber provided therein, a second piston movably mounted in said second chamber, a second piston rod secured to said second piston for movement therewith extending outwardly from said second housing parallel to said first piston rod, said second chamber being elongated, said second housing having a first opening formed therein which communicates with said second chamber intermediate the ends thereof, said second chamber being defined by a wall surface, said second conduit being in communication with said first opening, said second housing having a second opening formed therein which communicates with said second chamber at the end thereof, a third conduit in communication with said second opening, a nonmetallic annular seat embracing said second opening, said second piston being movable from a first position wherein said second piston sealably seats upon said seat to a second position wherein said second conduit is in communication with said first opening, said second chamber, said second opening and said third conduit, said second piston rod being extended from said second housing when said second piston is in its second position, actuating means on said first piston rod and being movable therewith to engage said second piston rod to move said second piston rod to its said first position to limit further flow of hydraulic fluid from said second chamber through said third conduit, the movement of said second piston rod to its said first position limiting the travel of said first piston rod in one direction, said second piston having a metallic only outer side surface which seats upon said annular seat, said second piston having a head portion which slidably engages said wall surface, said head portion having a thickness substantially less than the diameter of said first opening.
Claim 2
Dependent Claim
368 words
In combination, a hydraulic cylinder having a first housing defining a first chamber with a first piston movable thereon with a first piston rod extending through one end of said housing, a first conduit in communication with said first chamber on one side of said first piston, a second conduit in communication with said first chamber on the opposite side of said first piston, a stroke control unit comprising a second housing operatively secured to said housing and having a second chamber provided therein, a second piston movably mounted in said second chamber, a second piston rod secured to said second piston for movement therewith extending outwardly from said second housing parallel to said first piston rod, said second chamber being elongated, said second housing having a first opening formed therein which communicates with said second chamber intermediate the ends thereof, said second chamber being defined by a wall surface, said second conduit being in communication with said first opening, said second housing having a second opening formed therein which communicates with said second chamber at the end thereof, a third conduit in communication with said second opening, a nonmetallic annular seat embracing said second opening, said second piston being movable from a first position wherein said second piston sealably seats upon said seat to a second position wherein said second conduit is in communication with said first opening, said second chamber, said second opening and said third conduit, said second piston rod being extended from said second housing when said second piston is in its second position, actuating means on said first piston rod and being movable therewith to engage said second piston rod to move said second piston rod to its said first position to limit further flow of hydraulic fluid from said second chamber through said third conduit, the movement of said second piston rod to its said first position limiting the travel of said first piston rod in one direction, said second piston having a metallic only outer side surface which seats upon said annular seat, said second piston having a head portion which slidably engages said wall surface, said head portion having a thickness substantially less than the diameter of said first opening.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-06 | 1975-12-06 | 1976-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-06 | 1979-12-06 | 1980-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-06 | 1983-12-06 | 1984-06-06 | $7700.00 | Window Closed / Lapsed |