US3710988A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Injection molding machine
Assignee: Individual
•
Filing: 1970-09-21
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Granted: 1973-01-16
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Expires: 1990-09-21
Abstract
Abstract An injection molding machine comprising a feed screw which is rotatable and reciprocal in a plasticizing housing of a machine wherein the feed screw includes a head having a piston portion and a tapered nose portion projecting forwardly from the piston portion with the head including a generally central chamber therein communicated by means of passageways with the forward and rearward ends of said piston portion, and with there being centrally arranged movable ball valve means disposed in guided relation in said central chamber adapted for coaction with a valve seat for preventing return flow of plastic from the forward end of said piston portion to the rearward end thereof through said passageway means during the forward dispensing stroke of the feed screw.
Inventors
- 👤 E Moslo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:09
CPC Classifications
B; B29; B29C; B29C45/00; B29C45/17; B29C45/46; B29C45/47; B29C45/50; B29C45/52
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
251 words
Molding mechanism comprising in combination, an elongated plasticizing housing having an inlet for granular material and an outlet spaced from the inlet for plasticized material, feed screw means mounted within the housing for rotation and reciprocation therein and having thereon a screw thread which fits the interior of the housing, said feed screw means including a head adjacent an end thereof comprising a piston portion and a tapered nose portion projecting forwardly from the piston portion, said piston portion being adapted to have a sliding fit in said housing, a chamber in said head, a valve seat in said chamber first passageway means communicating said chamber with the forward end of said piston portion and other passageway means communicating said chamber with the rearward end of said piston portion, a ball valve member movably mounted in said chamber and adapted for seating engagement with said seat for preventing return of plasticized material from said forward end of said piston portion to said rearward end thereof upon the forward dispensing stroke of said feed screw means, and stop means in said chamber forwardly of said seat for engagement with said ball valve member to limit its forward movement during the flow of plasticized material from the rearward end of said piston portion to the forward end thereof and to locate the valve member generally centrally of said chamber in a direction transverse thereof, whereby plasticized material can flow evenly from said chamber about said valve member and out said first passageway means.
Claim 2
Dependent Claim
251 words
Molding mechanism comprising in combination, an elongated plasticizing housing having an inlet for granular material and an outlet spaced from the inlet for plasticized material, feed screw means mounted within the housing for rotation and reciprocation therein and having thereon a screw thread which fits the interior of the housing, said feed screw means including a head adjacent an end thereof comprising a piston portion and a tapered nose portion projecting forwardly from the piston portion, said piston portion being adapted to have a sliding fit in said housing, a chamber in said head, a valve seat in said chamber first passageway means communicating said chamber with the forward end of said piston portion and other passageway means communicating said chamber with the rearward end of said piston portion, a ball valve member movably mounted in said chamber and adapted for seating engagement with said seat for preventing return of plasticized material from said forward end of said piston portion to said rearward end thereof upon the forward dispensing stroke of said feed screw means, and stop means in said chamber forwardly of said seat for engagement with said ball valve member to limit its forward movement during the flow of plasticized material from the rearward end of said piston portion to the forward end thereof and to locate the valve member generally centrally of said chamber in a direction transverse thereof, whereby plasticized material can flow evenly from said chamber about said valve member and out said first passageway means.
Claim 3
Dependent Claim
46 words
A mechanism in accordance with claim 1 wherein a portion of said head is detachable from the remainder of said head of said feed screw means, and wherein said piston portion is partially formed on said remainder and partially on said detachable portion of said head.
Claim 4
Dependent Claim
75 words
A mechanism in accordance with claim 1 wherein said passageway means from said chamber to rearwardly of said piston portion communicates with the exterior of said screw means at the juncture of the screw flight with said head, the last mentioned passageway means comprising opposed passages communicating at the inner ends thereof with said chamber and each extending rearwardly therefrom at an angle of approximately 60* with respect to the lengthwise axis of said chamber.
Claim 5
Dependent Claim
94 words
A mechanism in accordance with claim 1 wherein said nose portion is of conical-like configuration and has recesses formed in opposite sides thereof, said recesses being spaced evenly from one another in a direction circumferentially of said nose portion, said passageway means communicating said chamber with the forward end of said piston portion opening into said recesses, and comprising a pair of passages diverging uniformly with respect to one another and with respect to the lengthwise axis of said chamber, said passages being disposed in a plane passing through said axis of said chamber.
Claim 6
Dependent Claim
109 words
A mechanism in accordance with claim 1 wherein the exit end of said first passageway means communicating said chamber to a point forwardly of said piston portion comprises an opening having a flared periphery and communicating with a recess in the side of said nose portion, said recess being defined in part by an end surface extending generally transverse to said nose portion with the lengthwise axis of said first passageway means being disposed in the plane of the lengthwise axis of said chamber and being generally perpendicular to said surface, the first mentioned lengthwise axis diverging with respect to the second mentioned lengthwise axis in a forward direction.
Claim 7
Dependent Claim
243 words
Molding mechanism comprising in combination, an elongated plasticizing housing having an inlet for granular material and an outlet spaced from the inlet for plasticized material, feed screw means mounted within the housing for rotation and reciprocation therein and having thereon a screw thread which fits the interior of the housing, said feed screw means including a head adjAcent an end thereof comprising a piston portion and a tapered nose portion projecting forwardly from the piston portion, said piston portion being adapted to have a sliding fit in said housing, a chamber in said head, a valve seat in said chamber, first passageway means communicating said chamber with the forward end of said piston portion and other passageway means communicating said chamber with the rearward end of said piston portion, a valve member mounted in said chamber and adapted for seating engagement with said seat for preventing return of plasticized material from said forward end of said piston portion to said rearward end thereof upon the forward dispensing stroke of said feed screw means, a portion of said head being detachable from the remainder of said head of said feed screw means, said piston portion being partially formed on said remainder and partially on said detachable portion of said head, and wherein said detachable portion of said head includes a shank projecting rearwardly, and means on said shank for fastening said detachable portion to the remainder of the head of said feed screw means.
Claim 8
Dependent Claim
243 words
Molding mechanism comprising in combination, an elongated plasticizing housing having an inlet for granular material and an outlet spaced from the inlet for plasticized material, feed screw means mounted within the housing for rotation and reciprocation therein and having thereon a screw thread which fits the interior of the housing, said feed screw means including a head adjAcent an end thereof comprising a piston portion and a tapered nose portion projecting forwardly from the piston portion, said piston portion being adapted to have a sliding fit in said housing, a chamber in said head, a valve seat in said chamber, first passageway means communicating said chamber with the forward end of said piston portion and other passageway means communicating said chamber with the rearward end of said piston portion, a valve member mounted in said chamber and adapted for seating engagement with said seat for preventing return of plasticized material from said forward end of said piston portion to said rearward end thereof upon the forward dispensing stroke of said feed screw means, a portion of said head being detachable from the remainder of said head of said feed screw means, said piston portion being partially formed on said remainder and partially on said detachable portion of said head, and wherein said detachable portion of said head includes a shank projecting rearwardly, and means on said shank for fastening said detachable portion to the remainder of the head of said feed screw means.
Claim 9
Dependent Claim
149 words
A mechanism in accordance with claim 1 wherein said chamber is of elongated cylindrical-like configuration and of a size to guide the movement of said ball valve member longitudinally of said head during a molding operation of said mechanism, said stop means in said chamber being adjacent the forward end thereof and limiting the forward movement of said valve member with respect to said chamber, said stop means having a configuration complementary to said ball valve member for locating the valve member generally centrally with respect to said chamber, said first passageway means comprising a pair of passages diverging with respect to one another and extending diagonally from said chamber outwardly to open onto said nose portion, the exit openings of said passages being diametrically opposed on said nose portion, the lengthwise axis of said passages being disposed in a plane passing through the lengthwise axis of said chamber.
Claim 10
Dependent Claim
97 words
A mechanism in accordance with claim 4 wherein each of said recesses is of a materially larger size than the cross-sectional size of the respective first mentioned passageway means coacting therewith, said recesses aiding in providing for smooth extrusion of plasticized material from the rearward end of said piston portion to the forward end thereof, each respective passage being enlarged adjacent its juncture with said chamber so as to permit more free flow of plasticized material from said chamber to said passages and past said ball valve member, when the latter is disposed against said stop means.
Claim 11
Dependent Claim
50 words
A mechanism in accordance with claim 1 wherein the axis of said passageway means communicating said chamber with the forward side of said piston portion is rectilinear and is disposed at an angle of approximately 22* with respect to a horizontal plane passing through the lengthwise axis of said head.
Claim 12
Dependent Claim
28 words
A mechanism in accordance with claim 1 wherein said plasticizing housing comprises a compression zone adjacent said head and a feed zone spaced rearwardly from said compression zone.
Claim 13
Dependent Claim
125 words
A mechanism in accordance with claim 1 wherein said passageway means communicating said chamber with the rearward end of said piston portion comprises diagonally extending substantially rectilinear passageways extending rearwardly at an angle of approximately 60* with respect to a horizontal plane through the lengthwise axis of said feed screw means, said passageways intersecting at said axis, and a longitudinally extending passageway section communicating with said passageways at said intersection, said valve seat defining the entrance way to said chamber from said passageway section, and said seat being of a configuration complementary to that of said ball valve member and when engaged by said valve member being adapted to close said passageway section and thus prevent communication between said chamber and said diagonally extending passageways.
Claim 14
Dependent Claim
26 words
A mechanism in accordance with claim 4 wherein said first passageway means communicating with said recesses have widened inner ends at their juncture with said chamber.
Claim 15
Dependent Claim
43 words
A mechanism in accordance with claim 4 wherein each of said recesses includes a generally planar end surface extending generally transverse of said nose portion, the axes of said passageway means communicating with said recesses opening into the latter in generally perpendicular relation.
References Cited (Backward Citations)
US3099861A
Cited
US3438393A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-16 | 1976-07-17 | 1977-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-16 | 1980-07-17 | 1981-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-16 | 1984-07-17 | 1985-01-16 | $7700.00 | Window Closed / Lapsed |