Four-section fully hydraulically operated crane boom having three individually supported single piston rams contained within fly section

Claim 2

A four-section fully hydraulically operated crane boom comprising inner and outer mid-secTions, and a fly section all telescopically inter-fitting within a base section, a first ram having its rod end connected with the base section and its cylinder connected with the inner mid-section of the boom near the rear ends of the cylinder and inner mid-section, said cylinder extending substantially forwardly of its point of connection with the inner mid-section, a second ram having connections with the inner and outer mid-sections, a core member extending over said second ram and connected with the outer midsection near the rear ends of the outer mid-section and core member, the rod end of the second ram connected with the core member near the forward end of the core member, a third ram having connections with the outer mid-section and the fly section of the boom, said rams individually supported and independently operable, a rest structure for the forward end portion of said cylinder of the first ram slidably contacting the core member, the vertical height of all said boom sections being nearly equal, and said fly section constructed to telescope over all of the rams in the retracted positions thereof to substantially enclose them.

Claim 3

A four-section fully hydraulically operated crane boom comprising inner and outer mid-sections, and a fly section all telescopically inter-fitting within a base section, a first ram having its rod end pivotally secured to said base section near the rear end of the base section and having its cylinder end pivotally connected with the inner mid-section near the rear ends of the cylinder and inner mid-section, the cylinder of said first ram extending substantially forwardly of its point of connection with the inner mid-section, a second ram having connections with the inner and outer mid-section, said second ram having its cylinder end connected to the inner mid-section, a hollow core member engaging over the second ram and connected near its forward end to the rod end of the second ram and connected near its rear end to the outer mid-section near the rear end of the outer mid-section, a third ram connected between the outer mid-section and the fly section of the boom, said rams individually supported and independently operable, a rest structure for the forward end portion of said cylinder of the first ram slidably contacting the core member, whereby retraction of said rams allows the fly section to telescope over all of the rams to substantially enclose them.

Claim 4

A four-section fully hydraulically operated crane boom comprising inner and outer mid-sections, and a fly section all telescopically inter-fitting within a base section, a first ram having its rod end pivotally secured to said base section near the rear end of the base section and having its cylinder end pivotally connected with the inner mid-section near the rear ends of the cylinder and inner mid-section, the cylinder of said first ram extending substantially forwardly of its point of connection with the inner mid-section, a second ram having connections with the inner and outer mid-section, said second ram having its cylinder end connected to the inner mid-section, a hollow core member engaging over the second ram and connected near its forward end to the rod end of the second ram and connected near its rear end to the outer mid-section near the rear end of the outer mid-section, a third ram connected between the outer mid-section and the fly section of the boom, said rams individually supported and independently operable, a rest structure for the forward end portion of said cylinder of the first ram slidably contacting the core member, whereby retraction of said rams allows the fly section to telescope over all of the rams to substantially enclose them.

Claim 5

The structure of claim 2 and said connection between the rod end of the first ram and said base section being a resilient pivotal connection with restrained freedom of movement in the vertical direction, the connection between the rear ends of the core member and outer mid-section also being a pivotal connection.

Claim 6

The structure of claim 2 in which said rest structure comprises a wear pad on the cylinder of the first ram near the forward end of the cylinder having sliding engagement with the core member and supporting the cantilevered end of the cylinder of the first ram in all operative positions of the boom.

Claim 7

A crane boom as set forth in claim 4 and another wear pad on said core member near its forward end having sliding engagement with a part of the fly section.

Claim 8

The structure of claim 2 and said hollow core member including a substantially flat top wall having side longitudinal edge portions which project outwardly of the opposite side walls of the core member, and said rest structure comprising a bearing and guide unit on the cylinder of the first ram near the forward end of the cylinder and including a wear pad slidably engaging the top wall of said core and a pair of laterally spaced opposed guide shoes engaging below said longitudinal edge portions in close proximity to the side walls of said core.

Claim 9

A crane boom as set forth in claim 2 in which said third ram has its rod end connected to said fly section and its cylinder end connected with the outer mid-section, and said first ram disposed bodily between tHe second and third rams in vertically stacked relation.

Claim 10

A crane boom as set forth in claim 2, and a wear pad on the cylinder of said third ram having sliding engagement with a part of said fly section.

Claim 11

A four-section fully hydraulically operated crane boom comprising inner and outer mid-sections, and a fly section all telescopically inter-fitting within a base section, a first ram having its rod end resiliently pivotally connected with restrained freedom of movement in the vertical direction with the base section and its cylinder connected with the inner mid-section of the boom near the rear ends of the cylinder and inner mid-section, the cylinder of said first ram extending substantially forwardly of its point of connection with the inner mid-section, a second ram having connections with the inner and outer mid sections, a core member extending over said second ram and pivotally connected with the outer mid-section near the rear ends of the outer mid-section and core member, the rod end of said second ram connected with the core member near the forward end of the core member, a rest structure for the forward end portion of said cylinder of the first ram slidably contacting the core member, a third ram having connections with the outer mid-section and the fly section of the boom, said rams individually supported and independently operable, said resilient pivotal connection comprising a cross pin element, a sleeve on the cross pin element, ball bearings supporting the opposite ends of the cross pin element, guide elements having vertical guide slots for said ball bearings, and cushioning springs above and below the ball bearings in said guide elements, whereby retraction of said rams allows the fly section to telescope over all of the rams to substantially enclose them.

Claim 12

A four-section fully hydraulically operated crane boom comprising inner and outer mid-sections, and a fly section all telescopically inter-fitting within a base section, a first ram having its rod end resiliently pivotally connected with restrained freedom of movement in the vertical direction with the base section and its cylinder connected with the inner mid-section of the boom near the rear ends of the cylinder and inner mid-section, the cylinder of said first ram extending substantially forwardly of its point of connection with the inner mid-section, a second ram having connections with the inner and outer mid sections, a core member extending over said second ram and pivotally connected with the outer mid-section near the rear ends of the outer mid-section and core member, the rod end of said second ram connected with the core member near the forward end of the core member, a rest structure for the forward end portion of said cylinder of the first ram slidably contacting the core member, a third ram having connections with the outer mid-section and the fly section of the boom, said rams individually supported and independently operable, said resilient pivotal connection comprising a cross pin element, a sleeve on the cross pin element, ball bearings supporting the opposite ends of the cross pin element, guide elements having vertical guide slots for said ball bearings, and cushioning springs above and below the ball bearings in said guide elements, whereby retraction of said rams allows the fly section to telescope over all of the rams to substantially enclose them.

Claim 13

The structure of claim 9 and said cushioning springs secured to top and bottom portions of said guide elements, and friction shoes connected with said springs and slidably contacting the peripheries of said ball bearings and urged yieldingly against the peripheries by said springs.

Claim 14

A four-section fully hydraulically operated crane boom comprising inner and outer mid-sections, and a fly section all telescopically inter-fitting within a base section, a first ram having its rod end resiliently pivotally connected with restrained freedom of movement in the vertical direction with the base section and its cylinder connected with the inner mid-section of the boom near the rear ends of the cylinder and inner mid-section, said cylinder extending substantially forwardly of its point of connection with the inner mid-section, a second ram having connections with the inner and outer mid-sections, a third ram having connections with the outer mid-sections and the fly section of the boom, said rams individually supported and independently operable, said resilient pivotal connection comprising a cross pin element, a sleeve on the cross pin element, ball bearings supporting the opposite ends of the cross pin element, guide elements having vertical guide slots for said ball bearings, and cushioning springs above and below the ball bearings in said guide elements, whereby retraction of said rams allows the fly section to telescope over all of the rams to substantially enclose them.

Claim 15

A four-section fully hydraulically operated crane boom comprising inner and outer mid-sections, and a fly section all telescopically inter-fitting within a base section, a first ram having its rod end resiliently pivotally connected with restrained freedom of movement in the vertical direction with the base section and its cylinder connected with the inner mid-section of the boom near the rear ends of the cylinder and inner mid-section, said cylinder extending substantially forwardly of its point of connection with the inner mid-section, a second ram having connections with the inner and outer mid-sections, a third ram having connections with the outer mid-sections and the fly section of the boom, said rams individually supported and independently operable, said resilient pivotal connection comprising a cross pin element, a sleeve on the cross pin element, ball bearings supporting the opposite ends of the cross pin element, guide elements having vertical guide slots for said ball bearings, and cushioning springs above and below the ball bearings in said guide elements, whereby retraction of said rams allows the fly section to telescope over all of the rams to substantially enclose them.

Claim 16

A crane boom as set forth in claim 11 and said cushioning springs secured to top and bottom portions of said guide elements, and friction shoes connected with said springs and slidably contacting the peripheries of said ball bearings and urged yieldingly against the peripheries by said springs.