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US 7,134,810 B2Granted
Yieldable prop having a yield section
AssigneeJennmar Corporation
InventorsJohn C. Stankus, John G. Oldsen
Life of this patent
Estimating the term…
Abstract
A yieldable prop having a first end and a second end includes a first hollow conduit, a second conduit slidably received in the first hollow conduit, and a clamp assembly positioned adjacent the juncture of the first hollow conduit and the second conduit. A yield section is provided at the end of the first and/or second conduits, or at the juncture of the first and second conduits. The yield section includes a shroud spaced from an inner pipe to provide a space to receive a collapsible insert. An end of a conduit is positioned in the space and compresses the insert when the compressive load on the prop exceeds the compressive load capacity of the insert.
Claims9
A yieldable prop comprising:
- a hollow conduit having a first end and an opposite second end, wherein the hollow conduit can support a predetermined compression load before collapsing;
- and
- a yield section comprising:
- a plate having a major surface;
- an outer sleeve having a first end and an opposite second end, the first end of the sleeve secured to the major surface of the plate;
- a pipe having a first end, a second opposite end, and a body between the first end and the second end of the pipe, the first end of the pipe secured to the major surface of the plate within the outer sleeve with outer surface of the pipe spaced from inner surface of the outer sleeve to provide a space between the pipe and the outer sleeve;
- and
- an insert in the space, wherein the insert can support a predetermined compression load before collapsing, and the predetermined compression load of the insert is less than the predetermined compression load of the hollow conduit, and
- wherein the first end of the hollow conduit is slidably received in the space with the insert between the major surface of the plate and the first end of the hollow conduit, and wherein the insert is at least not joined to the first end of the hollow conduit.
6 more elements
A yieldable prop comprising:
- a hollow first conduit having a first end and an opposite second end, wherein the first conduit can support a predetermined compression load before collapsing;
- a second conduit having a first end and an opposite second end with the first end of the second conduit slidably received in the second end of the first conduit, wherein the second conduit can support a predetermined compression load before collapsing;
- a surface of a second plate mounted on the second end of the second conduit;
- a yield section comprising:
- a first plate having a major surface;
- an outer sleeve having a first end and an opposite second end, the first end of the sleeve secured to the major surface of the first plate;
- a pipe having a first end, a second opposite end, and a body between the first end and the second end of the pipe, the first end of the pipe secured to the major surface of the plate within the outer sleeve with outer surface of the pipe spaced from inner surface of the outer sleeve to provide a space between the pipe and the outer sleeve;
- and
- an insert in the space, wherein the insert can support a predetermined compression load before collapsing, and the predetermined compression load of the insert is less than the predetermined compression load of the first and second conduits,
- wherein the first end of the hollow conduit is slidably received in the space with the insert between the major surface of the plate and the first end of the hollow conduit, and wherein the insert is at least not joined to the first end of the hollow conduit;
- and
- a securing arrangement to maintain the first and second plates in a predetermined spaced relationship to one another.
9 more elements
A yieldable prop, comprising:
- a first conduit having a first end and an opposite second end, wherein the first conduit is a hollow conduit and can support a predetermined compression load before collapsing;
- a second conduit having a first end and an opposite second end, with the first end of the second conduit slidably received in the second end of the first conduit to provide a conduit arrangement having a first end and an opposite second end, wherein the second conduit can support a predetermined compression load before collapsing;
- and
- a yield section mounted at the first end of the conduit arrangement, the yield section comprising:
- a first plate having a major surface;
- an outer sleeve having a first end and an opposite second end, with the first end of the outer sleeve securely mounted to the major surface of the first plate;
- an insert capable of supporting a predetermined compression load before collapsing, wherein the predetermined compression load of the insert is less than the predetermined compression load of the first and second conduits;
- a pipe having a first end, an opposite second end, and a body between the first end and the second end of the pipe, the first end of the pipe secured to the major surface of the first plate within the outer sleeve, with the outer surface of the pipe spaced from the inner surface of the outer sleeve to provide a space between the pipe and the outer sleeve, with the insert in the space, wherein the first end of the conduit arrangement is slidably received in the space, with the insert between the major surface of the first plate and the first end of the conduit arrangement;
- a first spacer between the first end of the conduit arrangement and the insert;
- a second spacer between the insert and the major surface of the first plate;
- a second plate having a surface, with the surface of the second plate mounted on the second end of the conduit arrangement;
- and
- a securing arrangement to maintain the first and second plates in a predetermined spaced relationship to one another.
10 more elements
Dependencies are inferred from the claim text.