US3791780A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vacuum pump
Assignee: Robinair Manufacturing Corp
•
Filing: 1972-05-11
•
Granted: 1974-02-12
•
Expires: 1992-05-11
Abstract
Abstract An improved vacuum pump of the rotary mechanical type having interchangeable component parts which may be assembled in ''''building block'''' fashion to provide single and multi-stage pumps built up from the same basic parts. The multi-stage pump may be provided with a switchable feature whereby the stages may be operated in series or in parallel, with automatic switching therebetween if desired. Both air ballast and oil injection are provided, the latter incorporating a check valve to control the supply of oil to the pumping chamber.
Inventors
- 👤 J Fritch
- 👤 D Brandeberry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:41
CPC Classifications
F; F04; F04C; F04C28/00; F04C28/02; F04C29/00; F04C29/02; F04C2220/00; F04C2220/50
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
121 words
In a rotary vacuum pump having at least one member defining a pumping chamber with a rotary displacer therein and an end plate overlying and closing one end of the chamber and mating with the chamber member, an oil reservoir atop said chamber, an oil sealing groove at the interface between the end plate and the chamber member and extending in circumferentially spaced relation around the chamber and communicating at the upper end with the oil reservoir, and passageway means establishing communication between the lower end of the oil sealing groove and the pumping chamber whereby oil flows from said reservoir downwardly through the oil groove and is admitted to said pumping chamber from the lower end of the oil groove.
Claim 2
Dependent Claim
121 words
In a rotary vacuum pump having at least one member defining a pumping chamber with a rotary displacer therein and an end plate overlying and closing one end of the chamber and mating with the chamber member, an oil reservoir atop said chamber, an oil sealing groove at the interface between the end plate and the chamber member and extending in circumferentially spaced relation around the chamber and communicating at the upper end with the oil reservoir, and passageway means establishing communication between the lower end of the oil sealing groove and the pumping chamber whereby oil flows from said reservoir downwardly through the oil groove and is admitted to said pumping chamber from the lower end of the oil groove.
Claim 3
Dependent Claim
35 words
A rotary vacuum pump as defined in claim 1 characterized by a pressure responsive check valve means for permitting flow from said oil sealing groove into said chamber and preventing flow in the reverse direction.
Claim 4
Dependent Claim
87 words
A rotary vacuum pump as defined in claim 1 characterized in that said oil reservoir comprises a housing abutting said at least one member and having a fluid inlet passage communicating with said chamber and adapted for connection with a device to be exhausted, and an oil sealing groove at the interface between said housing and said member and surrounding said fluid inlet to the chamber and communicating with the oil reservoir to provide an oil seal about the chamber inlet between said member and said housing.
Claim 5
Dependent Claim
55 words
A rotary vacuum pump as defined in claim 1 characterized in that said passageway means comprises a generally vertical passageway communicating at its lower end with said oil sealing groove and a generally horizontal passageway establishing communication between said vertical passageway and said chamber at a point spaced above said lowermost extremity of the groove.
Claim 6
Dependent Claim
74 words
A rotary vacuum pump as defined in claim 4 characterized in that pressure responsive check valve means is positioned in said vertical passageway to permit oil flow from said oil sealing groove to said chamber and prevent flow in the reverse direction, said valve means comprising a valve seat, a valve body above said seat for sealing engagement thereagainst and constant rate spring means engaging said valve body urging the body toward said seat.
Claim 7
Dependent Claim
78 words
The invention defined by claim 1 characterized in that there are a pair of said end plates closing opposite ends of the chamber and mating with the chamber member, and there is an oil groove as aforesaid at the interface between each end plate and the chamber member, and passageway means for establishing communication between the pair of oil grooves at the lower ends thereof, whereby oil flows downwardly through each oil groove for entry into the chamber.
Claim 8
Dependent Claim
24 words
The invention defined by claim 6 characterized in that valve means is provided for controlling flow between said oil sealing grooves and the chamber.
Claim 9
Dependent Claim
45 words
The invention defined by claim 1 characterized in that said pump includes a plurality of block-like members secured together in face-to-face relation defining a plurality of axially aligned pumping chambers and there is one of said oil sealing grooves at the interfaces between said members.
Claim 10
Dependent Claim
22 words
The invention defined by claim 8 characterized in that each of said grooves communicates at its upper end with said oil reservoir.
Claim 11
Dependent Claim
30 words
The invention defined by claim 9 characterized by passage-way means for establishing communication between all of the oil sealing grooves at their lower ends and one of said pumping chambers.
Claim 12
Dependent Claim
33 words
The invention defined by claim 10 characterized by pressure responSive check valve means in said passageway means for permitting oil flow into said chamber from said oil grooves but preventing reverse oil flow.
Claim 13
Dependent Claim
29 words
The invention defined by claim 1 characterized by the provision of valve means for controlling the amount of oil admitted to said pumping chamber from the oil sealing groove.
Claim 14
Dependent Claim
70 words
The invention defined by claim 12 characterized in that said valve means is responsive to a predetermined lower pressure in the pumping chamber than in the oil sealing groove to admit oil to the pumping chamber from the groove and responsive to a lesser or reverse pressure differential to prevent oil flow either into the chamber from the groove or reverse pressurization from the chamber to the oil sealing groove.
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) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |