US4679989A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pump shovel bulk unloader
Assignee: Graco Inc
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Filing: 1986-07-16
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Granted: 1987-07-14
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Expires: 2006-07-16
Abstract
Abstract An air-operated reciprocating pump is designed for use with a wide variety of materials having widely varying viscosities. The pump has a stroke which is adjustable so that the piston can operate either entirely within the cylinder or can extend out the bottom end of the cylinder at the end of the stroke for materials having an extremely high viscosity. The stroke adjustment is easily accessible in the area between the pump and the air motor.
Inventors
- 👤 Charles E. Harriman
- 👤 Donald S. Nii
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 14:15
CPC Classifications
F; F04; F04B; F04B15/00; F04B15/02; B; B67; B67D; B67D7/00; B67D7/06; B67D7/58; B67D7/62; B67D7/64; B67D7/645; F04B49/00; F04B49/12; F04B2015/026
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
91 words
A pump for pressurizing and transporting materials of varying viscosity, said pump comprising: a cylinder having an open bottom end; a piston reciprocally located in said cylinder and having top and bottom surfaces; a reciprocating source of power; a connecting rod connecting said piston and said power source, said piston oscillating between top and bottom positions; and means for adjusting the bottom position of said piston between a first position wherein said piston is located in said cylinder and a second position wherein said piston extends outside said open bottom end.
Claim 2
Dependent Claim
91 words
A pump for pressurizing and transporting materials of varying viscosity, said pump comprising: a cylinder having an open bottom end; a piston reciprocally located in said cylinder and having top and bottom surfaces; a reciprocating source of power; a connecting rod connecting said piston and said power source, said piston oscillating between top and bottom positions; and means for adjusting the bottom position of said piston between a first position wherein said piston is located in said cylinder and a second position wherein said piston extends outside said open bottom end.
Claim 3
Dependent Claim
16 words
The pump of claim 1 wherein said adjusting means adjusts said bottom position in discrete steps.
Claim 4
Dependent Claim
35 words
The pump of claim 2 wherein said adjusting means comprises: at least one hole in said connecting rod at least one hole in said power source and means for locating said holes in contiguous relationship.
Claim 5
Dependent Claim
14 words
The pump of claim 1 further comprising a check valve associated with said piston.
Claim 6
Dependent Claim
32 words
The pump of claim 4 said check valve comprising a passage in said piston connecting said surfaces and a plate check slideably mounted on said connecting rod to selectively cover said passage.
Claim 7
Dependent Claim
15 words
The pump of claim 5 wherein said plate check releasably contacts said piston top surface.
Claim 8
Dependent Claim
13 words
The pump of claim 1 wherein said power source is an air motor.
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) | 1990-07-13 | 1991-01-12 | 1991-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-13 | 1995-01-12 | 1995-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-13 | 1999-01-12 | 1999-07-14 | $7700.00 | Window Closed / Lapsed |