US3577613A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Portable molding apparatus
Assignee: Arthur D Little Inc
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Filing: 1968-04-16
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Granted: 1971-05-04
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Expires: 1988-04-16
Abstract
Abstract A portable molding apparatus for prestressed concrete members including a hollow mold body for receiving a charge of concrete and reinforcing strand for emplacement in the molded concrete. Mold end members, at least one of which is moveable, define opposite end portions of the body and include strand gripping means to receive and engage a portion of reinforcing strand to retain a strand suspended within the mold cavity. Releasing means provided on each end member are engageable with the gripping means to disengage the gripping means from the strand, and at least one of the end members is moveable with respect to the mold body with the releasing and gripping means engaged so that the strand can be withdrawn from the gripping means and the cast concrete member removed from the mold body.
Inventors
- 👤 William P Hidden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 13:01
CPC Classifications
B; B28; B28B; B28B23/00; B28B23/02; B28B23/04; B28B23/043
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
286 words
In a molding apparatus for molding prestressed concrete members having a mold body defining a cavity for receiving a charge of concrete and having means to support reinforcing strand within the cavity, the improvement comprising an adjustable variable locking means for maintaining the strand under a selected tensioning force with substantial accuracy, said locking means comprising: an anchoring member positioned in substantial alignment with said mold cavity; moveably mounted for translating movement with respect to said mold body; a locking member positioned adjacent said anchoring member and moveably mounted for translating movement with respect to said anchoring member within a selected range of distance, said locking member including strand gripping means to receive and releasably grip a free portion of the reinforcing strand supported within said cavity as said locking member translates with respect to said anchoring member; releasing means engageable with said strand-gripping means to disengage said gripping means from said strand; adjustable infinitely variable locking means positioned between said locking and anchoring members in engagement with and slidably moveable with respect to said locking member; and means to apply a force to said locking member to translate said locking member with respect to said anchoring member into a tensioning position within said range which subjects said strand to a tensioning force of predetermined magnitude; said variable locking means being infinitely adjustable between said anchoring and locking members to releasably retain said locking member in any selected tensioning position with respect to said anchoring member within said range, so that the strand tensioning force will be accurately maintained at a predetermined magnitude, and being further adjustable to permit said releasing means to engage with said gripping means and release the tensioning force from the strand.
Claim 2
Dependent Claim
286 words
In a molding apparatus for molding prestressed concrete members having a mold body defining a cavity for receiving a charge of concrete and having means to support reinforcing strand within the cavity, the improvement comprising an adjustable variable locking means for maintaining the strand under a selected tensioning force with substantial accuracy, said locking means comprising: an anchoring member positioned in substantial alignment with said mold cavity; moveably mounted for translating movement with respect to said mold body; a locking member positioned adjacent said anchoring member and moveably mounted for translating movement with respect to said anchoring member within a selected range of distance, said locking member including strand gripping means to receive and releasably grip a free portion of the reinforcing strand supported within said cavity as said locking member translates with respect to said anchoring member; releasing means engageable with said strand-gripping means to disengage said gripping means from said strand; adjustable infinitely variable locking means positioned between said locking and anchoring members in engagement with and slidably moveable with respect to said locking member; and means to apply a force to said locking member to translate said locking member with respect to said anchoring member into a tensioning position within said range which subjects said strand to a tensioning force of predetermined magnitude; said variable locking means being infinitely adjustable between said anchoring and locking members to releasably retain said locking member in any selected tensioning position with respect to said anchoring member within said range, so that the strand tensioning force will be accurately maintained at a predetermined magnitude, and being further adjustable to permit said releasing means to engage with said gripping means and release the tensioning force from the strand.
Claim 3
Dependent Claim
55 words
A molding apparatus in accordance with claim 1 wherein said variable locking means comprises a rotatable threaded member extending between said locking and anchoring members and engageable with said locking member upon threaded advancement to releasably maintain said locking member in a plurality of tensioning positions with respect to said anchoring member within said range.
Claim 4
Dependent Claim
56 words
A molding apparatus in accordance with claim 1 wherein said mold body is adapted to support a plurality of lengths of reinforcing strand and wherein said molding apparatus includes a corresponding plurality of locking members and variable locking means to individually apply and maintain a selected tension force in each of the plurality of reinforcing strands.
Claim 5
Dependent Claim
48 words
A molding apparatus in accordance with claim 2 wherEin said rotatable threaded member includes a portion threadably engaged with said anchoring member and an unthreaded portion slidably connected to said locking member so that said locking member translates with respect to said anchoring member on said unthreaded portion.
Claim 6
Dependent Claim
33 words
A portable molding apparatus in accordance with claim 4 including a pair of rotatable threaded members connected between said anchoring and locking members and uniformly spaced with respect to said strand gripping means.
Claim 7
Dependent Claim
140 words
A portable molding apparatus for molding prestressed concrete members comprising: a hollow mold body defining a cavity for receiving concrete to be molded and reinforcing strand for placement in the molded concrete; mold end members defining opposite end portions of said mold body; strand gripping means positioned on each end member to receive and engage a portion of reinforcing strand to retain a strand within said mold cavity; and releasing means on each end member engageable with said strand gripping means to disengage said gripping means from said strand; one of said end members being moveably mounted on said mold body and moveable with respect to said body, with the releasing means engaged with the gripping means, to withdraw the strand from the associated gripping means and thereby permit the removal of the cast concrete member from the mold body.
Claim 8
Dependent Claim
140 words
A portable molding apparatus for molding prestressed concrete members comprising: a hollow mold body defining a cavity for receiving concrete to be molded and reinforcing strand for placement in the molded concrete; mold end members defining opposite end portions of said mold body; strand gripping means positioned on each end member to receive and engage a portion of reinforcing strand to retain a strand within said mold cavity; and releasing means on each end member engageable with said strand gripping means to disengage said gripping means from said strand; one of said end members being moveably mounted on said mold body and moveable with respect to said body, with the releasing means engaged with the gripping means, to withdraw the strand from the associated gripping means and thereby permit the removal of the cast concrete member from the mold body.
Claim 9
Dependent Claim
64 words
A portable molding apparatus in accordance with claim 6 wherein both end members are moveably mounted on said mold body and are moveable with respect to said body, with the releasing means engaged with the gripping means, to withdraw the strand from the gripping means on both end members and thereby permit the ready removal of the cast concrete member from the mold body.
Claim 10
Dependent Claim
64 words
A portable molding apparatus in accordance with claim 7 wherein said mold body is open ended and wherein both mold end members are slidably mounted on the adjacent ends of said body and are moveable from an opened position spaced from said mold body into a closed position against the adjacent mold body ends to thereby define the end portions of said mold cavity.
Claim 11
Dependent Claim
113 words
A portable molding apparatus in accordance with claim 6 wherein each of said end members includes a first plate containing said strand gripping means and a second plate containing said strand releasing means and wherein said first and second plates are moveable with respect to each other from a relatively spaced position, permitting said gripping means to engage with the strand, into a relatively close position engaging said releasing means with said gripping means so that the gripping means releases the strand and the strand can be withdrawn from said gripping means, and further wherein each end member includes locking means to selectively retain said first and second plates in said spaced position.
Claim 12
Dependent Claim
86 words
A portable molding apparatus in accordance with claim 9 wherein said strand gripping means comprises strand chucks mounted on each of said first plates and having chuck jaws moveable into engagement with reinforcing strand to restrain movement of said strand through said chucks inwardly into said mold body, and wherein said strand releasing means comprises projection means mounted on each of said second plates and engageable with said chuck jaws to release said jaws and permit said strand to move inwardly relative to said end members.
Claim 13
Dependent Claim
79 words
A portable molding apparatus in accordance with claim 1 wherein said strand gripping means comprises strand chucks mounted on said locking member and having chuck jaws moveable into engagement with said free portion of reinforcing strand, and wherein said releasing means comprises projection means mounted on said anchoring member and engageable with said chuck jaws as said locking member is spaced adjacent said anchoring member to release said jaws and permit the strand to be removed from said chucks.
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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) | 1974-05-03 | 1974-11-02 | 1975-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-03 | 1978-11-02 | 1979-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-03 | 1982-11-02 | 1983-05-04 | $7700.00 | Window Closed / Lapsed |