Patent US3924651A successfully refreshed from Google Patents.
US3924651A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Metering or injection element
Assignee: Dow Chemical Co
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Filing: 1974-10-15
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Granted: 1975-12-09
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Expires: 1994-10-15
Abstract
Abstract The present invention relates to an injection element, especially a three-way metering valve for plastic molding machines, comprising an injection nozzle which opens into a mixing chamber, a return flow port which returns the supplied material flow in circulation in the case of an interruption of the injection process, and a control element for the switchover of the material flow from the injection step to the return step and vice versa, wherein a return valve is positioned in the end of said return flow port; said injection valve and said return valve having identical or analogous characteristics of their flow and opening cross-sections at any degree of opening thereof; and said injection valve and said return valve being adapted to be operated by said control element in opposite directions for the initiation of the injection process.
Inventors
- 👤 Ludwig Jakob Hippel
- 👤 Alex Pemsl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:14
CPC Classifications
G; G05; G05D; G05D11/00; G05D11/006; B; B29; B29B; B29B7/00; B29B7/74; B29B7/76; B29B7/7615; B29B7/7626; B29B7/7631; B29B7/7636; B29B7/7642; B29B7/7663; B29B7/7684; Y; Y10; Y10T; Y10T137/00; Y10T137/2496; Y10T137/2559; Y10T137/2574; Y10T137/2605; Y10T137/2642; Y10T137/8593; Y10T137/85954; Y10T137/86493; Y10T137/86879; Y10T137/86895; Y10T137/87571; Y10T137/87676; Y10T137/87684
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
296 words
In plastic molding equipment comprising a mixing chamber having at least one injection port, a reservoir for a liquid plastic component to be injected into the mixing chamber, an improved injection element to supply the component to said chamber injection port, and pump means and associated ducts connecting the injection element to said pump and reservoir to deliver the liquid component to said element and return excess to the reservoir, said improved injection element comprising: a housing for said element having component feed, injection and return ports, said element injection port being formed to be received in said chamber injection port, and said feed and return ports making connection with said ducts, a pair of shiftable valve members disposed in said housing in back-to-back relation, each having a free end received in one of said injection and return ports, and control means dispoSed intermediate and positively interconnecting said members for reciprocal movement thereof simultaneously between opposite limiting positions in said housing; annular valve seats formed in said housing at said injection and return ports and cooperating respectively with the free ends of said shiftable valve members to define said limiting positions, said valve seat in said housing injection port being disposed to be substantially coterminus with the injection port of the mixing chamber; said valve seats and valve members defining annular flow passages of such shape and configuration, respectively, as to provide analogous flow passages complementary to each other in all positions of said shiftable valve members between said limiting positions; and adjustment means accessible externally of said injection element housing for varying the position of said return valve seat in said housing relative to said injection valve seat to simultaneously and commonly adjust the flow cross-sectional areas of said injection and return annular flow passages.
Claim 2
Dependent Claim
296 words
In plastic molding equipment comprising a mixing chamber having at least one injection port, a reservoir for a liquid plastic component to be injected into the mixing chamber, an improved injection element to supply the component to said chamber injection port, and pump means and associated ducts connecting the injection element to said pump and reservoir to deliver the liquid component to said element and return excess to the reservoir, said improved injection element comprising: a housing for said element having component feed, injection and return ports, said element injection port being formed to be received in said chamber injection port, and said feed and return ports making connection with said ducts, a pair of shiftable valve members disposed in said housing in back-to-back relation, each having a free end received in one of said injection and return ports, and control means dispoSed intermediate and positively interconnecting said members for reciprocal movement thereof simultaneously between opposite limiting positions in said housing; annular valve seats formed in said housing at said injection and return ports and cooperating respectively with the free ends of said shiftable valve members to define said limiting positions, said valve seat in said housing injection port being disposed to be substantially coterminus with the injection port of the mixing chamber; said valve seats and valve members defining annular flow passages of such shape and configuration, respectively, as to provide analogous flow passages complementary to each other in all positions of said shiftable valve members between said limiting positions; and adjustment means accessible externally of said injection element housing for varying the position of said return valve seat in said housing relative to said injection valve seat to simultaneously and commonly adjust the flow cross-sectional areas of said injection and return annular flow passages.
Claim 3
Dependent Claim
85 words
An injection element as defined in claim 1, wherein said means positively interconnecting said valve members comprises a control piston, a chamber in said housing defining a control cylinder in which said control piston is axially reciprocable, and plunger means connected to opposite faces of said piston, said valve members being located on the free ends of said plungers; and ports in said housing communicating with opposite sides of said piston for fluid pressure communication therewith to axially shift said piston and associated valve member.
Claim 4
Dependent Claim
51 words
An injection element as defined in claim 2, wherein said valve members at the free ends of said plungers are of frustoconical configuration and said injection and return seats are of mating configuration, whereby the smallest cross-sectional area of said element injection port is coterminous with the mixing chamber injection port.
Claim 5
Dependent Claim
189 words
An injection element as defined in claim 2, wherein said housing is formed to provide a second cylinder within one end of which said return valve seat is slidably received to make a piston fit therein, a plug threadedly received in the other end of said second cylinder, and a compression spring between said seat and plug; a fluid medium filling said second cylinder between said seat and plug, a sight gage and duct means in said housing communicating said second cylinder with said level gage, restricting valve means having movable and stationary members located in said fluid medium duct; a third cylinder in said housing and a piston therein, said last piston on one face carrying said movable member of said restricting valve means to move it into and out of restricting relation to the stationary member thereof, said housing having duct means communicating with the opposite face of said piston, and other duct means connecting to said control cylinder, whereby control pressure applied to said control piston to open said injection valve is also applied to said piston in said third cylinder to close said restricting valve.
Claim 6
Dependent Claim
31 words
An injection element as defined in claim 1, wherein the limiting reciprocal movement of said control means is equivalent to maximum range of adjustment of said return valve seat adjustment means
Claim 7
Dependent Claim
37 words
An injection element as defined in claim 5, wherein said adjustment means is responsive to pressure at the return valve seat, and duct means communicating said adjustment means with the upstream side of said return valve seat.
Claim 8
Dependent Claim
137 words
An injection element as defined in claim 6, wherein said adjustment means comprises a plug on which said return valve seat is supported, a bore in said housing in which said valve seat is slidable and in which said plug is also threadedly received to provide axial adjustment and a gear rack interconnecting them, and a housing for reciprocation of said piston members therein, a pinion connected to said plug and engaging said gear rack to be rotated thereby upon movement of said opposed piston memBers, said duct means from said return valve communicating with one end of said piston housing to impose component return pressure on the associated piston, and port means at the other end of said piston housing to communicate an external control pressure to the other of said pistons in said adjustment device.
Claim 9
Dependent Claim
26 words
An injection element as defined in claim 5, wherein said adjustment means includes a member responsive to pump speed and volume pumped per unit of time.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-08 | 1979-06-09 | 1979-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-08 | 1983-06-09 | 1983-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-08 | 1987-06-09 | 1987-12-09 | $7700.00 | Window Closed / Lapsed |