Patent US3750895A successfully refreshed from Google Patents.
US3750895A
Expired / Lapsed
US
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Yard jib crane
Assignee: Richier SA
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Filing: 1971-01-22
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Granted: 1973-08-07
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Expires: 1991-01-22
Abstract
Abstract A yard jib or tower crane having a vertical mast, a hoist boom supporting a load hoist truck being pivotally supported for rotation about the mast end including a first beam and a second beam attached to said first beam and being radially movable relative thereto; a counterweight boom supporting a balancing weight compensating for the moments about the mast generated by said truck-supporting boom; and a control including a replaceable profile cam for predetermined radial displacement of said second beam relative to the first beam and of the balancing weight along the counterweight boom during angular displacement in a horizontal plane of said boom about the mast.
Inventors
- 👤 P Durand
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:30
CPC Classifications
B; B66; B66C; B66C9/00; B66C9/14; B66C23/00; B66C23/62; B66C23/72; B66C2700/00; B66C2700/03; B66C2700/0385; B66C2700/0392
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
348 words
Improvements in yard jib or tower cranes with a radially travelling hoist truck, of the type including a vertical tower having a mast head and a jib assembly rotatably mounted on the mast head of the tower, said jib assembly comprising a hoist truck boom, a load hoist truck being movable along said hoist truck boom, said truck having a tackle, and a counterweight boom carrying a balance weight adapted to be moved radially relative to said counterweight boom for compensating the moment created at the mast head level by the hoist truck boom, said hoist truck boom further including a main beam connected to the tower mast head and a secondary beam adapted to be moved radially in either direction relative to said main beam, control and driving means for imparting said movement to the secondary beam; tackle means adapted to be actuated by said control and driving means for causing the movement of said counterweight in a direction opposed to the direction of movement of said secondary beam, said control and drive means controlling the movements of the secondary beam being operative in one position thereof with a member held against rotation in relation to the truck boom and adapted to reproduce the desired path of the free end of the secondary beam during 360* rotation in a horizontal plane of the jib assembly about the mast head, and being operative in another position thereof with replaceable profile cam means, said caM means detecting on said element and for each angular position of said jib assembly relative to said mast head the optimum radial position to be imparted to said secondary beam, and further control means adapted to be actuated by said replaceable profile cam means, said last mentioned control means being operatively connected with said secondary beam for automatically setting the latter in said optimum radial position, whereby the no-load moment of the crane remains substantially unchanged during the movement of said secondary beam which takes place without any appreciable change in the radial position of the truck in relation to the tower mast head.
Claim 2
Dependent Claim
348 words
Improvements in yard jib or tower cranes with a radially travelling hoist truck, of the type including a vertical tower having a mast head and a jib assembly rotatably mounted on the mast head of the tower, said jib assembly comprising a hoist truck boom, a load hoist truck being movable along said hoist truck boom, said truck having a tackle, and a counterweight boom carrying a balance weight adapted to be moved radially relative to said counterweight boom for compensating the moment created at the mast head level by the hoist truck boom, said hoist truck boom further including a main beam connected to the tower mast head and a secondary beam adapted to be moved radially in either direction relative to said main beam, control and driving means for imparting said movement to the secondary beam; tackle means adapted to be actuated by said control and driving means for causing the movement of said counterweight in a direction opposed to the direction of movement of said secondary beam, said control and drive means controlling the movements of the secondary beam being operative in one position thereof with a member held against rotation in relation to the truck boom and adapted to reproduce the desired path of the free end of the secondary beam during 360* rotation in a horizontal plane of the jib assembly about the mast head, and being operative in another position thereof with replaceable profile cam means, said caM means detecting on said element and for each angular position of said jib assembly relative to said mast head the optimum radial position to be imparted to said secondary beam, and further control means adapted to be actuated by said replaceable profile cam means, said last mentioned control means being operatively connected with said secondary beam for automatically setting the latter in said optimum radial position, whereby the no-load moment of the crane remains substantially unchanged during the movement of said secondary beam which takes place without any appreciable change in the radial position of the truck in relation to the tower mast head.
Claim 3
Dependent Claim
46 words
Tower crane as set forth in claim 1, comprising rollers disposed on either one of said main beam or secondary beam and engaging a suitable track means carried by the other beam for guiding said secondary beam during its translation in relation to said main beam.
Claim 4
Dependent Claim
208 words
Tower crane as set forth in claim 1, the means controlling the movement of said secondary beam in relation to the main beam comprising a double-winding winch drum, means for actuating said winch drum, at least one rope having its two runs adapted to be partly wound on said drum and having free ends attached, respectively, to said secondary beam and to a fixed point of the counterweight boom, a set of return pulleys over which said rope runs pass being carried by the end of said counterweight which is closest to the tower, a further set of pulleys forming a tackle with said set of return pulleys being held against translation on said counterweight boom, a third set of pulleys carried on the other end of said counterweight, a fourth set of pulleys held against translation on said counterweight boom forming another rope tackle with said third set of pulleys and having its rope anchored to said counterweight boom through the end of one of its runs and to said secondary beam through the end of its other run, each said tackle comprising a number of runs equal or substantially equal to the ratio of the weight of the counterweight to the weight of the secondary beam.
Claim 5
Dependent Claim
120 words
Tower crane as set forth in claim 3, wherein said counterweight comprises a fixed element having a predetermined weight so as to balance the moment resulting from the product of the length of the main beam by one-half of the maximum load likely to be carried by said main beam and of a movable element of which the weight is a multiple of the weight of said secondary beam, said movable element of the counterweight being connected on the one hand to said secondary beam and on the other hand to said counterweight boom through tackle equal or substantially equal in number to the ratio of the weight of said movable counterweight element to the weight of said secondary beam.
Claim 6
Dependent Claim
136 words
Tower crane as set forth in claim 3, wherein the hoist rope is unwound from a winch disposed at a fixed location on the boom and, after passing over a plurality of said return pulleys, returned to the free end of the main beam towards the hoist tackle carried by the truck and then directed towards a pulley disposed at a free end of said secondary beam and adapted, by forming a tackle with another pulley disposed at the root of said secondary beam, to return to said last-named pulley and subsequently be directed towards a free end of said main beam to which the free end of the run is anchored, whereby the movement of said secondary beam cannot interfere with the vertical position of the load, irrespective of the truck position along the beam.
Claim 7
Dependent Claim
44 words
Tower crane as set forth in claim 5, wherein said load truck comprises two sets of rollers, one set of said rollers engaging a track carried by said main beam, and the other set of rollers engaging a track carried by said secondary beam.
Claim 8
Dependent Claim
147 words
Tower crane as set forth in claim 6, wherein a first pair of coaxial rollers disposed on the truck end nearest to the head of the boom and forming part of the set of rollers engaging the track of the main beam is shifted vertically upwards by a distancE which is substantially equal to the upward shift of a second pair of coaxial rollers disposed at the tower end of said truck and forming part of the set of rollers engaging said secondary beam, said distance being determined as a function of the gradient of inclined surfaces provided at the outer end of said main beam and at the inner end of said secondary beam, respectively, so that the transfer of said truck from one beam to the other can take place smoothly, irrespective of the defect of parallelism of the tracks carried by these two beams.
Claim 9
Dependent Claim
27 words
Tower crane as set forth in claim 4, wherein said load truck comprises only one set of rollers engaging a single track carried by said secondary beam.
Claim 10
Dependent Claim
122 words
Tower crane as set forth in claim 6, wherein said load truck driving means comprise a winch drum of the double winding type and a rope wound on said drum and having two runs, one run being attached with its free end to said truck and passing over a return pulley carried by said counterweight boom, the other run of said rope passing in succession over a pulley disposed at the head of said main beam and over another pulley disposed at the root of said secondary beam to constitute a tackle, and thereafter about another pulley mounted to a free end of said secondary beam before returning towards the truck to which the free end of said other run is attached.
Claim 11
Dependent Claim
67 words
Tower crane as set forth in claim 7, wherein said truck driving means comprise a double-winding winch drum from which two rope runs extend, each run passing over a return pulley disposed for one run at a first end of said secondary beam and for the other run at the other end of the same beam, the free ends of said runs being anchored to said truck.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-06 | 1977-02-05 | 1977-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-06 | 1981-02-05 | 1981-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-06 | 1985-02-05 | 1985-08-07 | $7700.00 | Window Closed / Lapsed |