US3203317A - Low oil level safety lock and air pocket vent - Google Patents
Low oil level safety lock and air pocket vent Download PDFInfo
- Publication number
- US3203317A US3203317A US312060A US31206063A US3203317A US 3203317 A US3203317 A US 3203317A US 312060 A US312060 A US 312060A US 31206063 A US31206063 A US 31206063A US 3203317 A US3203317 A US 3203317A
- Authority
- US
- United States
- Prior art keywords
- ram
- fluid
- air pocket
- vent
- air
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B66—HOISTING; LIFTING; HAULING
- B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
- B66F7/00—Lifting frames, e.g. for lifting vehicles; Platform lifts
- B66F7/10—Lifting frames, e.g. for lifting vehicles; Platform lifts with platforms supported directly by jacks
- B66F7/16—Lifting frames, e.g. for lifting vehicles; Platform lifts with platforms supported directly by jacks by one or more hydraulic or pneumatic jacks
- B66F7/18—Lifting frames, e.g. for lifting vehicles; Platform lifts with platforms supported directly by jacks by one or more hydraulic or pneumatic jacks by a single central jack
Definitions
- a low oil level lock of the type mentioned must be placed near the lower end of the plunger or ram so that maximum fluid transfer between the ram and cylinder is possible before the fluid is cut-off.
- air which is entrapped in the fluid, and is otherwise in the system and escapes while in the outer cylinder to collect in an annular pocket between the ram and cylinder walls near the upper end of the cylinder.
- This area of compressible air is undersirable in the fluid lift system, because of the compressible cushion it provided, and must be vented or exhausted in some way.
- FIGURE 1 is a coss-sectioned side plan view of a lift shown in a lower disposed position and including the present invention.
- FIGURE 2 is a cross-sectional view of the lift shown by FIGURE 1 with the ram disposed in an elevated position.
- FIGURE 3 is a fragmentary cross-sectioned view similar to FIGURE 2 with a low oil level condition existing within the ram.
- FIGURE 4 is an enlarged cross-sectional view of a fragmentary part of the lift shown by the previous figures and showing certain features in greater detail.
- FIGURE 5 is an enlarged cross-sectional view of the vent tube check valve of this invention as seen in the plane of the line 55 of FIGURE 4.
- the semi-hydraulic hoist or lift 10 shown in the drawings includes an outer cylinder member 12 having a plunger or ram 14 provided therein and having an air pressure line 16 connected thereto for introducing air into the top of the ram and forcing hydraulic fluid 18 from the ram into the cylinder to cause the elevation of the former.
- the outer cylinder member 12 is normally embedded in the ground below the ground level line 20 and includes a cylindrical case 22 having a bottom closure 24.
- the air pressure line 16 extends through the bottom closure 24 and a packing gland or stufiing box 26 is provided at the top of the cylinder to receive the plunger or ram 14 in relatively sealed and guided relation therethrough.
- the plunger or ram member 14 includes a smaller cylindrical body member 28 which is concentrically disposed within the outer cylinder body member 12. It includes a bottom closure 30 having a packing gland 32 through which is received the air pressure line 16. The top of the ram cylinder 28 also includes a closure 34 with a guide rod 36 provided thereon and depending into the air pressure line 16.
- a carrier frame 38 is provided on a upper disposed end of the plunger or ram 14 for whatever lift serving purpose is desired.
- a fluid passage 40 is provided through the bottom wall 30 of the plunger or ram 14.
- a perforated tube 42 has one end disposed in the fluid passage 40 and the other end secured to a guide fixture 44 secured to the upper closure wall 34 of the ram cylinder.
- a float 46 is provided in the perforated tube 42. AS will later be described, the float 46 is adapted to close the fluid passage 40 when the fluid level in the ram 14 falls below a prescribed level and before an air passage is created between the ram and the outer cylinder.
- the plunger or ram In the lower disposed position of the ram 14 within the outer cylinder 12, as shown by FIGURE 1, the plunger or ram is essentially filled with the fluid 18.
- the annular space 48 between the ram and the cylinder is also filled with fluid, the oil lock float 46 is disposed high in the perforated tube 42 and the fluid passage 40 is open between the two cylinders.
- the plunger or ram 14 is raised by the introduction of air through the air pressure supply line 16 into the top of the ram. This forces the fluid 18 through the passage 40 and into the outer cylinder 12. As the fluid level in the ram falls, the float 46 in the perforated tube 42 drops With the level of the fluid.
- the fluid in the ram is und r greater pressure than in the cylinder; as necessary to affect the flow of fluid from the ram to the cylinder.
- the fluid pressure becomes equal in the ram and the outer cylinder.
- the air pressure is released in the ram, n the fluid pressure is greater in the cylinder and fluid is forced through the restricted passage 40 back into the ram.
- a vent tube 52 is shown vertically disposed within the ram 14- and having its upper disposed end 54 extended through an opening 56 in the side wall of the ram and welded thereto.
- the open end of the vent tube 52 extends through the ram wall and is disposed for alignment with the air pocket 50 when the ram is at its fully raised position.
- the lower end 58 of the vent tube is extended in spaced relation to the lower end or bottom of the ram and below the low oil level mark determined by the seating of the float 46 in the fluid passage 40.
- vent tube will pass fluid ther-ethrough in the course of raising the ram since the fluid pressure is greater in the ram than in the cylinder. However, this is of no great consequence during the elevation of the ram since fluid is being passed through the passage 40 anyway.
- air will be vented from the air pocket 59. Although there will be some fluid transferred through the vent tube during the descent of the ram this, again, is of no consequence.
- the unobstructed openended vent tube serves perfectly well. However, if the air pressure in the ram is not cut-off before the low level reserve is forced by this air pressure through the vent tube then an open passage is create-d through to the outer cylinder and the safety of the low oil level lock float 46 is completely avoided.
- a check valve device 60 is provided at the lower end of the vent tube 52.
- the check valve device 66 includes a steel ball member 62 which is provided within a larger bore 64 preformed within the end of the vent tube and a ball check seat 66 which is provided thereon and further in the vent tube.
- a cotter pin 68 is extended laterally through the vent tube sufliciently below the ball check 66 so that the weighted ball 62 is normally disposed off the valve seat 66.
- An air pocket vent for vertically oriented semihydraulic lifts and the like including an air pressure receptive and fluid exhausting ram disposed within an outer cylinder receptive of the fluid exhausted from said ram for the elevation of said ram relative thereto, and which have an air pocket formed therebetween and in the outer cylinder, and comprising:
- vent passage means carried by said ram
- vent passage means being vertically disposed and open at the upper end thereof externally of said ram and for communication with the air pocket in the outer cylinder
- vent passage means having the lower disposed end thereof open within said ram near the lower end of said ram and below the low oil level mark therefore
- check valve means operatively disposed within said vent tube and responsive to greater pressure in said ram than at said air pocket end for closure thereof and a reverse pressure condition for the opening thereof and venting of said air pocket.
- said check valve means being provided at the lower disposed end of said vent tube and below the low oil level mark within said ram.
- said check valve means including a ball check member disposed near the ram end of said passage means and a receptive seat disposed next adjacent thereto and on the air pocket side thereof.
- said check valve means including a weighted ball provided in the lower disposed end of said vent passage means and a receptive seat provided in said passage means next adjacent thereto and thereover.
- An air pocket vent for vertically oriented semihydraulic lifts and the like including an air pressure receptive and fluid exhausting ram disposed within an outer cylinder receptive of the fluid exhausted from said ram for the elevation of said ram relative thereto, and which have an air pocket formed therebetween and in the outer cylinder and comprising:
- vent tube disposed in said ram and having one end thereof extend through the side wall thereof for open communication with the air pocket of the outer cylinder externally thereof
- vent tube being vertically disposed and having the other end thereof open in said ram below the air pocket end thereof and below the low oil level mark within said ram
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Geology (AREA)
- Mechanical Engineering (AREA)
- Structural Engineering (AREA)
- Self-Closing Valves And Venting Or Aerating Valves (AREA)
Description
Claims (1)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US312060A US3203317A (en) | 1963-09-27 | 1963-09-27 | Low oil level safety lock and air pocket vent |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US312060A US3203317A (en) | 1963-09-27 | 1963-09-27 | Low oil level safety lock and air pocket vent |
Publications (1)
Publication Number | Publication Date |
---|---|
US3203317A true US3203317A (en) | 1965-08-31 |
Family
ID=23209701
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US312060A Expired - Lifetime US3203317A (en) | 1963-09-27 | 1963-09-27 | Low oil level safety lock and air pocket vent |
Country Status (1)
Country | Link |
---|---|
US (1) | US3203317A (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3363511A (en) * | 1965-10-20 | 1968-01-16 | Joyce Cridland Co | Lift mechanism with low oil control |
US3415342A (en) * | 1967-06-28 | 1968-12-10 | Joyce Cridland Co | Vehicle lifting apparatus |
US3555971A (en) * | 1967-08-12 | 1971-01-19 | Messrs Markisches Werk Gmbh | High pressure lift device for power vehicles and the like |
US5390586A (en) * | 1994-03-28 | 1995-02-21 | Jones; Peter D. | Self-bleeding hydraulic cylinder |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2254699A (en) * | 1940-09-23 | 1941-09-02 | Rotary Lift Company | Lift |
US2550882A (en) * | 1947-03-19 | 1951-05-01 | Wayne Pump Co | Hoist safety valve |
US2588285A (en) * | 1950-05-27 | 1952-03-04 | Harold C Schott | Air bleeder for vehicle lifts |
US3112676A (en) * | 1959-06-16 | 1963-12-03 | Amalgamated Dental Co Ltd | Hoist |
-
1963
- 1963-09-27 US US312060A patent/US3203317A/en not_active Expired - Lifetime
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2254699A (en) * | 1940-09-23 | 1941-09-02 | Rotary Lift Company | Lift |
US2550882A (en) * | 1947-03-19 | 1951-05-01 | Wayne Pump Co | Hoist safety valve |
US2588285A (en) * | 1950-05-27 | 1952-03-04 | Harold C Schott | Air bleeder for vehicle lifts |
US3112676A (en) * | 1959-06-16 | 1963-12-03 | Amalgamated Dental Co Ltd | Hoist |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3363511A (en) * | 1965-10-20 | 1968-01-16 | Joyce Cridland Co | Lift mechanism with low oil control |
US3415342A (en) * | 1967-06-28 | 1968-12-10 | Joyce Cridland Co | Vehicle lifting apparatus |
US3555971A (en) * | 1967-08-12 | 1971-01-19 | Messrs Markisches Werk Gmbh | High pressure lift device for power vehicles and the like |
US5390586A (en) * | 1994-03-28 | 1995-02-21 | Jones; Peter D. | Self-bleeding hydraulic cylinder |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4223693A (en) | Counterbalance valve | |
US3203317A (en) | Low oil level safety lock and air pocket vent | |
US3955797A (en) | Swimming pool lift | |
US4892028A (en) | Fluid operated circuit for controlling a dual post hydraulic lift assembly | |
EP1260479B1 (en) | Cushioned actuator | |
JP6871626B2 (en) | lift device | |
US3394842A (en) | Pressure release device for a hydraulic tank | |
US2637302A (en) | Low oil control | |
US3486528A (en) | Vent valve having dynamic valve opening structure | |
US2705502A (en) | Air venting device for the cylinder of a hydraulic vehicle lift | |
US3447421A (en) | Vehicle lift | |
US3060900A (en) | Vehicle lifting mechanism | |
US1711549A (en) | Hydraulic jack | |
US3991659A (en) | Fail safe apparatus for load lifts | |
US2550882A (en) | Hoist safety valve | |
US2970577A (en) | Hydraulic lift | |
US2734597A (en) | pelouch | |
US3363511A (en) | Lift mechanism with low oil control | |
US3179014A (en) | Low oil level control device for hydraulic lifts | |
US3051141A (en) | Hydraulic lift | |
CN216687330U (en) | Anti-falling device based on lifting of stirring equipment cover | |
US4014515A (en) | Snubber for one end lift jacks | |
US3377981A (en) | Level indicator | |
US2535759A (en) | Hydraulic bumper jack | |
US3974764A (en) | Exhaust valve |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: TA ACQUISITION CORP. SOUTHFIELD, MI A CORP. OF CA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:DURA CORPORATION A NY CORP.;REEL/FRAME:004011/0573 Effective date: 19820212 |
|
AS | Assignment |
Owner name: DURA CORPORATION 26877 NORTHWEST HIGHWAY BOX 267, Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:DURA CORPORATION, A NY CORP.;REEL/FRAME:004049/0796 Effective date: 19820917 |
|
AS | Assignment |
Owner name: DURA CORPORATION, 26877 NORTHWEST HIGHWAY, BOX 267 Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:DURA CORPORATION, A CORP OF CA.;REEL/FRAME:004661/0877 Effective date: 19830815 Owner name: DURA CORPORATION, A CORP OF MI., MICHIGAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:DURA CORPORATION, A CORP OF CA.;REEL/FRAME:004661/0877 Effective date: 19830815 |