Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
260 words
For a large material handling apparatus comprising a telescoping crane boom assembly having two or more extensible and retractable sections, each section comprising a longitudinal top plate, a pair of side webs extending downwardly from opposite longitudinal edges of the top plate and appropriately secured thereto, a bottom plate appropriately secured to the lower edges of the side webs to provide a lower or compression flange and to close the boom section, and web stiffeners rigidly secured to the side webs in longitudinally spaced relation and extending between the top and bottom plates of the boom section, an arrangement of web stiffeners mounted on each side web of each extensible and retractable boom section, the arrangement comprising first and second pluralities of web stiffeners, each stiffener of the first plurality of web stiffeners being mounted on the web at a first angle of tilt in longitudinally spaced relation and directed toward the front of the boom section, each stiffener of the second plurality of web stiffeners being mounted on the web at a second angle of tilt in longitudinally spaced relation and being directed toward the rear of the boom section, with the innermost stiffener of each of the first and second pluralities of stiffeners intersecting at a changeover point generally provided at a midpoint of the boom section, the apex of the intersecting stiffeners being directed to the compression or lower flange of the boom section, the changeover point generally corresponding to the changeover from positive to the negative shear in a movable boom section under cantilever end loading.
Claim 2
Dependent Claim
260 words
For a large material handling apparatus comprising a telescoping crane boom assembly having two or more extensible and retractable sections, each section comprising a longitudinal top plate, a pair of side webs extending downwardly from opposite longitudinal edges of the top plate and appropriately secured thereto, a bottom plate appropriately secured to the lower edges of the side webs to provide a lower or compression flange and to close the boom section, and web stiffeners rigidly secured to the side webs in longitudinally spaced relation and extending between the top and bottom plates of the boom section, an arrangement of web stiffeners mounted on each side web of each extensible and retractable boom section, the arrangement comprising first and second pluralities of web stiffeners, each stiffener of the first plurality of web stiffeners being mounted on the web at a first angle of tilt in longitudinally spaced relation and directed toward the front of the boom section, each stiffener of the second plurality of web stiffeners being mounted on the web at a second angle of tilt in longitudinally spaced relation and being directed toward the rear of the boom section, with the innermost stiffener of each of the first and second pluralities of stiffeners intersecting at a changeover point generally provided at a midpoint of the boom section, the apex of the intersecting stiffeners being directed to the compression or lower flange of the boom section, the changeover point generally corresponding to the changeover from positive to the negative shear in a movable boom section under cantilever end loading.
Claim 3
Dependent Claim
29 words
An arrangement of stiffeners as claimed in claim 1 wherein opposite ends of each stiffener are also rigidly secured to respective top and bottom plates of the boom section.
Claim 4
Dependent Claim
58 words
The arrangement of stiffeners as claimed in claim 1 wherein the first angle of tilt for each stiffener for the first plurality of web stiffeners is equal to the second angle of tilt for each stiffener of the second plurality of web stiffeners, with said first and second angles reversely positioned on opposite sides of the changeover point.
Claim 5
Dependent Claim
68 words
The arrangement of web stiffeners as claimed in claim 1 wherein the first and second angles of tilt are greater than 90° when measured from the longitudinal axis of the boom section to the longitudinal axis of the stiffener, such angle being measured counterclockwise for the stiffeners directed to the front of the boom section and clockwise for the stiffeners directed to the rear of the boom section.
Claim 6
Dependent Claim
70 words
The arrangement of web stiffeners as claimed in claim 1 wherein the first and second angles of tilt are greater than 90° but less than 135° when measured from the longitudinal axis of the boom section to the longitudinal axis of the stiffener, such angle being measured counterclockwise for stiffeners directed to the front of the boom section and clockwise for stiffeners directed to the rear of the boom section.
Claim 7
Dependent Claim
101 words
The arrangement of stiffeners as claimed in claim 1 wherein a plane transverse to the longitudinal axis of the boom section passes through the critical changeover point, a pair of web stiffeners intersect at a compressive flange of the plates abutting the web to form a V-shaped configuration at the critical changeover point, with respective first and second pluralities of web stiffeners associated with respective first and second stiffeners of the pair of intersecting web stiffeners and spaced outwardly therefrom allochirally with respect to the critical changeover point along each side web of the boom section in parallel longitudinally spaced relationship.