US3746494A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for making concrete tubes
Assignee: MASCHINENFAB ETTLINGEN DT
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Filing: 1971-10-13
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Granted: 1973-07-17
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Expires: 1991-10-13
Abstract
Abstract An apparatus for producing concrete tubes using a vertical tubular mold with a rotating piston-like pressing device moving upwards axially inside the mold. The piston-like pressing device is operated in such a manner that as the torque required for rotation of the piston-like pressing device decreases owing to a decrease in the supply of concrete, the rate of upward travel of the piston is decreased. An impeller is located above the pressing device which can be rotated at a higher speed and in opposed sense with regard to the rotational speed and sense of rotation of the piston-like pressing device.
Inventors
- 👤 F Gauger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 20:50
CPC Classifications
B; B28; B28B; B28B21/00; B28B21/02; B28B21/10; B28B21/22; B28B21/24
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
191 words
An apparatus for molding concrete tubes comprising: a. an upright female mold having an interior surface defining a mold cavity possessing a substantially vertical axis; b. a piston-like pressing device disposed within said female mold; c. means for rotating said pressing device within said mold cavity about said vertical axis of said female mold cavity; d. lifting means for moving said pressing device along said axis of rotation; e. rotary smoothing rollers forming part of said pressing device aligned for rolling upon concrete located between said pressing device and said female mold; f. an impeller arranged above said pressing device for centrifugally propelling unset concrete into a circular formation against the interior surface of said female mold into a position to be worked by said pressing device, and g. means responsive to operation of said rotating means for regulating the speed of operation of said lifting means as a function of the torque exerted by said rotating means upon said pressing device, so that during decrease of said torque the lifting speed of said pressing device decreases, and during increase of said torque the lifting speed of said pressing device increases.
Claim 2
Independent Claim
191 words
An apparatus for molding concrete tubes comprising: a. an upright female mold having an interior surface defining a mold cavity possessing a substantially vertical axis; b. a piston-like pressing device disposed within said female mold; c. means for rotating said pressing device within said mold cavity about said vertical axis of said female mold cavity; d. lifting means for moving said pressing device along said axis of rotation; e. rotary smoothing rollers forming part of said pressing device aligned for rolling upon concrete located between said pressing device and said female mold; f. an impeller arranged above said pressing device for centrifugally propelling unset concrete into a circular formation against the interior surface of said female mold into a position to be worked by said pressing device, and g. means responsive to operation of said rotating means for regulating the speed of operation of said lifting means as a function of the torque exerted by said rotating means upon said pressing device, so that during decrease of said torque the lifting speed of said pressing device decreases, and during increase of said torque the lifting speed of said pressing device increases.
Claim 3
Dependent Claim
121 words
An apparatus as defined in claim 1, further comprising: a hydraulic ram forming part of said lifting means, a supply pump, first duct means connecting said supply pump with said hydraulic ram, second duct means connecting said first duct means with said responsive means, said responsive means including valve means, reservoir means communicating with said valve means for receiving hydraulic fluid medium, third duct means for supplying fluid medium to said rotating means for said pressing device, and fourth duct means connecting said third duct means with said valve means for causing said valve means to open when the pressure in said third duct means decreases and to close said valve means when the pressure in said third duct means increases.
Claim 4
Dependent Claim
53 words
An apparatus as defined in claim 2, wherein said valve means conprises a plunger arranged in a cylinder, one end of said cylinder being connected with said fourth duct means, said valve means further comprising a spring at an opposite end of said plunger, said valve means providing an infinitely variable throttling action.
Claim 5
Dependent Claim
22 words
An aPparatus as defined in claim 3, wherein said spring can be adjusted to regulate the degree of compaction of the concrete.
Claim 6
Dependent Claim
37 words
An apparatus as defined in claim 1, wherein said impeller comprises two substantially superimposed spacedly arranged frusto-conical discs and impeller blades arranged therebetween, said discs being disposed to throw the concrete in a downward and outward direction.
Claim 7
Dependent Claim
22 words
An apparatus as defined in claim 5 further comprising impeller blades mounted on and above the uppermost one of said two discs.
Claim 8
Dependent Claim
16 words
An apparatus as defined in claim 5, wherein said impeller blades are substantially spiral in shape.
Claim 9
Dependent Claim
27 words
An apparatus as defined in claim 1, further including means for rotating said impeller at a greater rotational speed than the rotational speed of said pressing device.
Claim 10
Dependent Claim
32 words
An apparatus as defined in claim 8, wherein said rotating means for said impeller serves to rotate said impeller in a direction opposite to the direction of rotation of said pressing device.
Claim 11
Independent Claim
160 words
An apparatus for molding concrete tubes comprising: a. an upright female mold having an interior surface defining a mold cavity possessing a substantially vertical axis; b. a piston-like pressing device disposed within said female mold; c. means for rotating said pressing device within said mold cavity about said vertical axis of said female mold cavity; d. lifting means for moving said pressing device along said axis of rotation; e. an impeller arranged above said pressing device for centrifugally propelling unset concrete into a circular formation against the interior surface of said female mold into a position to be worked by said pressing device; and f. means for separately driving said impeller at a greater rotational speed than the rotational speed of said pressing device in order to obtain an increased degree of compaction of the concrete, said driving means for said impeller serving to rotate said impeller in a direction opposite to the direction of rotation of said pressing device.
Claim 12
Independent Claim
160 words
An apparatus for molding concrete tubes comprising: a. an upright female mold having an interior surface defining a mold cavity possessing a substantially vertical axis; b. a piston-like pressing device disposed within said female mold; c. means for rotating said pressing device within said mold cavity about said vertical axis of said female mold cavity; d. lifting means for moving said pressing device along said axis of rotation; e. an impeller arranged above said pressing device for centrifugally propelling unset concrete into a circular formation against the interior surface of said female mold into a position to be worked by said pressing device; and f. means for separately driving said impeller at a greater rotational speed than the rotational speed of said pressing device in order to obtain an increased degree of compaction of the concrete, said driving means for said impeller serving to rotate said impeller in a direction opposite to the direction of rotation of said pressing device.
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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) | 1976-07-16 | 1977-01-15 | 1977-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-16 | 1981-01-15 | 1981-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-16 | 1985-01-15 | 1985-07-17 | $7700.00 | Window Closed / Lapsed |