US3726557A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Handling grab
Assignee: Electricite de France SA
•
Filing: 1971-06-23
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Granted: 1973-04-10
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Expires: 1991-06-23
Abstract
Abstract The grab comprises a hollow cylindrical body which is connected to a suspension and control unit and in which grappling claws are displaced simultaneously between a position of engagement with a load to be handled and a position of disengagement therefrom. Each claw is supported by two parallel metallic rods which are fastened together along their entire length or only at one end. At least one rod which is of hollow construction, is connected at one end to the exterior and at the other end to a source of control fluid. Said fluid is brought to a temperature which is different from the ambient temperature, thereby causing differential expansion of the two rods and displacement of the claws.
Inventors
- 👤 E Ventre
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:07
CPC Classifications
G; G21; G21C; G21C19/00; G21C19/02; G21C19/10; G21C19/105; Y; Y02; Y02E; Y02E30/00; Y02E30/30; Y10; Y10S; Y10S294/00; Y10S294/906
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
123 words
A handling grab comprising a hollow cylindrical body connected to a suspension and control unit and in which grappling claws are displaced simultaneously between a position of engagement with a load to be handled and a position of disengagement therefrom, wherein each claw is supported by two parallel metallic rods which are fastened together at least at one end thereof, at least one of said rods being of hollow construction and extended internally by means of a passageway which provides a communication with the exterior and being connected to a source of control fluid, said fluid being brought to a temperature which is diffErent from the ambient temperature so as to cause differential expansion of the two rods and displacement of the claws.
Claim 2
Dependent Claim
123 words
A handling grab comprising a hollow cylindrical body connected to a suspension and control unit and in which grappling claws are displaced simultaneously between a position of engagement with a load to be handled and a position of disengagement therefrom, wherein each claw is supported by two parallel metallic rods which are fastened together at least at one end thereof, at least one of said rods being of hollow construction and extended internally by means of a passageway which provides a communication with the exterior and being connected to a source of control fluid, said fluid being brought to a temperature which is diffErent from the ambient temperature so as to cause differential expansion of the two rods and displacement of the claws.
Claim 3
Dependent Claim
16 words
A grab in accordance with claim 1, wherein the rods are formed of the same metal.
Claim 4
Dependent Claim
42 words
A grab in accordance with claim 2, wherein the rods have the same length and are parallel to the axis of the body when there is no circulation of control fluid, the claws of the grab being in the position of engagement.
Claim 5
Dependent Claim
58 words
A grab in accordance with claim 1, wherein the hollow body comprises a lateral opening through which the extremity of each claw passes in the position of engagement and a base pierced with slots so as to permit discharge of the control fluid during the greater part of the displacement of the claws towards the position of disengagement.
Claim 6
Dependent Claim
35 words
A grab in accordance with claim 4, wherein the rod which is located at the greatest distance from the extremity of each claw passes through said claw and the control fluid circulates within said rod.
Claim 7
Dependent Claim
12 words
A grab in accordance with claim 1, wherein both rods are hollow.
Claim 8
Dependent Claim
17 words
A grab in accordance with claim 1, wherein the rods are fastened together along their entire length.
Claim 9
Dependent Claim
18 words
A grab in accordance with claim 1, wherein a thermal decoupling means is interposed between the two rods.
References Cited (Backward Citations)
US3253853A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-09 | 1976-10-09 | 1977-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-09 | 1980-10-09 | 1981-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-09 | 1984-10-09 | 1985-04-10 | $7700.00 | Window Closed / Lapsed |