Patent US3757718A successfully refreshed from Google Patents.
US3757718A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for forming hollow articles of work-stengthenable plastic materials
Assignee: Shell USA Inc
•
Filing: 1971-05-27
•
Granted: 1973-09-11
•
Expires: 1991-05-27
Abstract
Abstract This application discloses method and apparatus for forming flanged hollow articles of solid-work-strengthenable tenaciously stretachable plastically flowable materials, particularly crystalline polymers, such as polyethylene polypropylene, and the like, and article made thereby, wherein a female die unit with a tubular portion has an annular (but not necessarily always circular) peripherally confined blank-holding recess seat at one end, the female die unit being formed of separable parts, when desired; wherein independently power-actuated rim-clamping means having axial movement clamp a rim portion of a blank securely in said recess seat against pull-in and with the added function of squeezing inventory material of the rim inwardly, when desired; and wherein an independently power-actuated axially movable article-forming plunger moves through said clamping means, preferably being guided thereby said sealed, to force the unclamped inner portion of the blank through the female die unit to pull bottom inventory material outward without extrusion action to form the sidewall of the article. An opposed cooperating independently power-actuated axially movable bottom plunger may be provided to act against the bottom of the blank to control its shape during and at the end of the forming action, and, if desired, to eject the formed article. Means may be provided for supplying to or removing fluid from one or both sides of the blank to assist the flow of material and in ejection of the article, when desired. The arrangement of the rim-clamping means relative to the sidewall of the tubular portion of the female die unit and the shape of the forming plunger assist in the flow of material and in establishing the desired thickness of the sidewall of the article. Means also may be provided for biaxially working the material in the rim, as by circumferential movement of pressure means acting thereon.
Inventors
- 👤 H Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:54
CPC Classifications
B; B29; B29C; B29C43/00; B29C43/02; B29C43/16; B21; B21C; B21C23/00; B21C23/007; B21C23/02; B21C23/04; B21C23/14; B29C43/32; B29C43/36; B29C43/361; B29C51/00; B29C51/002; B29C51/08; B29C51/082; B29C67/00; B29C67/0003; B29C2043/3615; B29C2043/3618; B29C2043/3631; B29C43/42; B29K; B29K2023/00; B29K2023/10; B29K2023/12; B29K2055/00; B29K2086/00
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
43 words
The method as set forth in claim 1, which further comprises: compressing the residual bottom inventory material after completion of the sidewall drawing action by continued action of the forming body against a fixed opposed body to form the bottom of the article.
Claim 2
Dependent Claim
62 words
The method as set forth in claim 1, which further comprises: controllably increasing the compressing action on the rim portion of the blank after it has been gripped and while the inner portion is being formed into the sidewall in tension and substantially free from compression to extrude rim inventory material inward to further assist in forming the sidewall of the article.
Claim 3
Dependent Claim
25 words
The method as set forth in claim 1, which further comprises: working the rim portion of the blank material circumferentially after it has been clamped.
Claim 4
Dependent Claim
23 words
The method as set forth in claim 4, wherein the rim portion is worked while the sidewall is being drawn out in tension.
Claim 5
Dependent Claim
54 words
The method as set forth in claim 1, wherein the rim of the initial blank is clamped, compressed, and formed in an exteriorly closed seat recess provided on the separable parts of an axially divided die unit; and, after the article has been formed, separating the die unit parts transversely and removing the article.
Claim 6
Dependent Claim
28 words
The method as set forth in claim 6, which further comprises: working the rim material circumferentially while positioned in the seat recess of the separable die unit parts.
Claim 7
Independent Claim
205 words
The method of forming hollow flanged articles of a material which is strengthenable by working in the solid state from a sheet blank, which comprises: gripping the peripheral rim portion of a sheet blank formed of said material, wHich is in the solid state at a workable temperature, by relative axial movement between an annular transverse recessed exteriorly-closed seat and a cooperating annular telescoping transverse-ended clamping means with sufficient axial pressure to hold the rim portion against bodily pull-in; maintaining compression on said rim by said annular clamping means for forcing rim inventory material inward during sidewall formation; engaging the inner portion of the blank, in a state free from compression thinning, by an axially movable forming plunger which forms, with the inner edge of the seat, an orifice of less radial thickness than the thickness of the blank; and continuing the axial movement of the forming plunger relative to the gripped rim to thin the blank in shear through said orifice and entrain bottom inventory material in tension and substantially free from compression on the end of the forming plunger; and by continued axial movement to draw out inventory material in tension and substantially free from compression to form the sidewall of the article.
Claim 8
Independent Claim
190 words
The method of forming a hollow flanged article of a material which is strengthenable by working the solid state from a sheet blank, which comprises: gripping the peripheral rim portion of a blank of said material, which is in the solid at a workable temperature, between an annular transverse seat and a cooperating annular transverse clamping means with sufficient axial pressure to hold the rim portion against bodily pull-in; engaging the inner portion of the blank by an axially movable forming body to entrain bottom inventory material on the end of the forming body; continuing the axial movement of said forming body to draw out bottom inventory material in tension to form the sidewall of the article; and controllably introducing fluid between the lower end of the forming body and the upper surface of the material while the forming body is moving axially to aid the draw-out of bottom inventory material from beneath the bottom of the forming body; the pressure of the fluid introduced being so controlled as to maintain the blank material in engagement with the forward side periphery of the forming body during its sidewall-forming axial movement.
Claim 9
Dependent Claim
28 words
The method as set forth in claim 9, which further comprises: increasing the fluid pressure at the end of the sidewall-forming axial movement to further expand the article.
Claim 10
Dependent Claim
49 words
The method as set forth in claim 9, which further comprises: engaging the bottom surface of the material beneath the forming body by an opposed body with sufficient pressure to aid in the feed-out of bottom inventory material but not enough pressure to cause extrusion of bottom inventory material.
Claim 11
Dependent Claim
28 words
The method as set forth in claim 11, which further comprises: controllably supplying fluid between the opposed body and the bottom surface of the material during article formation.
Claim 12
Dependent Claim
43 words
The method as set forth in claim 9, which further comprises: compressing the bottom inventory material at the end of the sidewall drawing action by continued action of the forming body against a fixed opposed body to form the bottom of the article.
Claim 13
Dependent Claim
39 words
The method as set forth in claim 13, which further comprises: supplying fluid between the lower surface of the formed article and said opposed body to shape the bottom of the article against the bottom of the forming body.
Claim 14
Dependent Claim
54 words
The method as set forth in claim 13, which further comprises: forming the article in an axially divided die unit; and after the article has been formed, separating the parts of the die unit; and moving the formed article axially on said opposed body to move it clear of the forming space for removal.
Claim 15
Independent Claim
171 words
The method of forming a hollow flanged article of a material which is strengthenable by working in the solid state from a sheet blank, which comprises: gripping the peripheral rim portion of a blank of said material, which is in the solid state at a workable temperature, between an annular transverse exteriorly-closed seat and a cooperating annular transverse-ended telescoping clamping means with sufficient axial pressure to hold the rim portion against bodily pull-in; engaging the inner portion of the blank, in a state free from compression thinning, by an axially movable forming body to entrain bottom inventory material in tension and substantially free from compression on the end of the forming body; continuing the axial movement of said forming body to draw out bottom inventory material in tension and substantially free from compression to form the sidewall of the article; and introducing an opposed body against the lower surface of the material but with less pressure than would cause extrusion of bottom inventory material while the forming body is moving axially.
Claim 16
Dependent Claim
29 words
The method as set forth in claim 16 wherein fluid is introduced between said opposed body and said lower surface during the time when said opposed body is introduced.
References Cited (Backward Citations)
US2468697A
Cited
US2878513A
Cited
CH332588A
Cited
US2854694A
Cited
US3341644A
Cited
US3324509A
Cited
US3184524A
Cited
US3259942A
Cited
US3510913A
Cited
US3496597A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-10 | 1977-03-12 | 1977-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-10 | 1981-03-12 | 1981-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-10 | 1985-03-12 | 1985-09-11 | $7700.00 | Window Closed / Lapsed |