US3786935A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Overhead crane
Assignee: Whiting Corp
•
Filing: 1972-05-22
•
Granted: 1974-01-22
•
Expires: 1992-05-22
Abstract
Abstract An overhead crane characterized by its redundant or double-safe features. The crane has two separate ropes with one end of each rope attached to the drum and the other end attached to an equalizer. Each rope, intermediate its opposite ends, is reeved over sheaves in the sheave nest and on the load block in such manner that each rope provides at least four active parts (i.e., load-supporting lines) running to the four horizontal quadrants of the load block with respect to the vertical center line therethrough. With this system and arrangement the load block will be supported by two independent sets having at least four active rope parts or lines of support in each set in such a manner that if a rope breaks or fails for any reason, at least one remaining complete set of at least four active parts provided by the undamaged rope will assume full support with little or no appreciable impact load occurring and with only small and acceptable swinging or twisting movement imparted to the lead. Additional redundancy and double-safety is provided by: constructing the crane hook so it has two separate load paths into the load block; having two complete gear trains between the hoist motor and the drum assembly with each being capable of handling the rated load with a normal factor of safety; having safety lugs to catch the drum hubs in case of shaft failure; having safety retainers for all sheaves in the sheave nest and in the load block to sustain the load upon failure of any sheave or its supporting shaft; and, having the equalizer bar boxed or caged in with load supporting members and provided with bumpers at opposite ends.
Inventors
- 👤 J Vlazny
- 👤 M Coston
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:53
CPC Classifications
B; B66; B66D; B66D1/00; B66D1/54; B66D3/00; B66D3/04; B66D3/06; B66D2700/00; B66D2700/02; B66D2700/026; B66D2700/028
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
322 words
In a crane comprising a horizontal drum having two separate ropes wound thereon with one end of each rope secured to said drum to one of the opposite sides of the mid-portion thereof, an upper sheave nest having at least two parallel nest sheaves, a load block suspended beneath said sheave nest having at least one pair of load block sheaves on each side of a vertical center plane including the vertical center line of said block, and an equalizer having the other two ends of said ropes secured thereto to one of the opposite sides of the mid-point thereof, the improvements comprising having said load block sheaves disposed in planes substantially parallel to said vertical center plane with the opposite ends of the horizontal diameter of each of said load block sheaves coinciding with the locii of two corners of a horizontal quadrilateral the locii of the remaining two corners of which coincide with the opposite ends of the horizontal diameter of one of said load block sheaves disposed on the opposite side of said vertical center plane, having each of said two ropes having parts reeved over one of said nest sheaves and under two of said load block sheaves which are disposed on opposite sides of said vertical center plane the horizontal diameters of which form two opposite sides of one of said quadilaterals, having each sheave in said upper sheave nest in a vertical plane at right angles to said vertical center plane, having at least two sheaves in said upper sheave nest horizontally offset with one of said ropes reeved over one offset sheave and the other rope being reeved over the other offset sheave, said equalizer extending in a generally horizontal direction at right angles to said vertical center plane, and having shock absorber means operatively connected with said equalizer so as to dampen the shifting movement thereof which occurs when either of said ropes breaks.
Claim 2
Dependent Claim
322 words
In a crane comprising a horizontal drum having two separate ropes wound thereon with one end of each rope secured to said drum to one of the opposite sides of the mid-portion thereof, an upper sheave nest having at least two parallel nest sheaves, a load block suspended beneath said sheave nest having at least one pair of load block sheaves on each side of a vertical center plane including the vertical center line of said block, and an equalizer having the other two ends of said ropes secured thereto to one of the opposite sides of the mid-point thereof, the improvements comprising having said load block sheaves disposed in planes substantially parallel to said vertical center plane with the opposite ends of the horizontal diameter of each of said load block sheaves coinciding with the locii of two corners of a horizontal quadrilateral the locii of the remaining two corners of which coincide with the opposite ends of the horizontal diameter of one of said load block sheaves disposed on the opposite side of said vertical center plane, having each of said two ropes having parts reeved over one of said nest sheaves and under two of said load block sheaves which are disposed on opposite sides of said vertical center plane the horizontal diameters of which form two opposite sides of one of said quadilaterals, having each sheave in said upper sheave nest in a vertical plane at right angles to said vertical center plane, having at least two sheaves in said upper sheave nest horizontally offset with one of said ropes reeved over one offset sheave and the other rope being reeved over the other offset sheave, said equalizer extending in a generally horizontal direction at right angles to said vertical center plane, and having shock absorber means operatively connected with said equalizer so as to dampen the shifting movement thereof which occurs when either of said ropes breaks.
Claim 3
Dependent Claim
10 words
The improvement of claim 1 wherein said quadrilaterals are trapezoids.
Claim 4
Dependent Claim
11 words
The improvement of claim 2 wherein said trapezoids are substantially congruent.
Claim 5
Dependent Claim
14 words
The improvement of claim 1 wherein said equalizer is carried on the crane super-structure.
Claim 6
Dependent Claim
14 words
The improvement of claim 1 wherein said equalizer is carried on said crane block.
Claim 7
Dependent Claim
21 words
The improvement of claim 1 wherein the diagonally opposed corners of each quadrilateral are approximately equidistant from said vertical center line.
Claim 8
Dependent Claim
56 words
The improvement of claim 1 wherein said equalizer is substantially paraLlel with said drum and said one end of each rope attached to said equalizer has its opposite end secured to said drum on that side of the mid-portion thereof which is the more removed from where the said one end is attached to said equalizer.
Claim 9
Dependent Claim
38 words
The improvement of claim 1 wherein said equalizer comprises a beam pivotally mounted intermediate its ends and wherein a shock absorber is operatively connected to each end of said equalizer beam so as to dampen the movement thereof.
Claim 10
Dependent Claim
45 words
The improvement of claim 1 wherein said equalizer comprises a pair of spaced aligned arms each of which is pivotally mounted adjacent its outer end and wherein a shock absorber is operatively connected to each of said arms so as to dampen the movement thereof.
Claim 11
Dependent Claim
35 words
The improvement of claim 1 wherein said equalizer comprises an elongated frame member mounted for horizontal reciprocal movement and wherein a shock absorber is operatively connected with said frame member to dampen the movement thereof.
Claim 12
Dependent Claim
153 words
In a crame comprising a drum, an upper sheave nest having at least two nest sheaves, an equalizer, and a load block suspended beneath said sheave nest and having at least two load block sheaves on each opposite side, the improvements comprising, having two separate ropes with one rope wound on and secured at one end to one longitudinal portion of the drum and with the other rope wound on and secured at one end to the other longitudinal portion of the drum, the opposite ends of each rope being secured to said equalizer on opposite sides of the pivot or mid-point thereof, and with each rope intermediate its ends being reeved over at least one nest sheave and under at least one load block sheave on each side of said block, and a dual load hook carried by said load block having separate load attaching means and separate substantially co-incident load paths.
Claim 13
Dependent Claim
153 words
In a crame comprising a drum, an upper sheave nest having at least two nest sheaves, an equalizer, and a load block suspended beneath said sheave nest and having at least two load block sheaves on each opposite side, the improvements comprising, having two separate ropes with one rope wound on and secured at one end to one longitudinal portion of the drum and with the other rope wound on and secured at one end to the other longitudinal portion of the drum, the opposite ends of each rope being secured to said equalizer on opposite sides of the pivot or mid-point thereof, and with each rope intermediate its ends being reeved over at least one nest sheave and under at least one load block sheave on each side of said block, and a dual load hook carried by said load block having separate load attaching means and separate substantially co-incident load paths.
Claim 14
Dependent Claim
25 words
In the crane called for in claim 11 the further improvement comprising a sheave guard under each nest sheave and over each load block sheave.
Claim 15
Dependent Claim
24 words
In the crane called for in claim 11 the further improvement wherein said crane drum is driven from opposite ends through separate gear trains.
Claim 16
Dependent Claim
36 words
The crane called for in claim 11 the further improvement wherein said drum has a hub at each opposite end and a safety block is mounted under the hub on each opposite end of said drum.
Claim 17
Dependent Claim
59 words
In the crame called for in claim 11 the further improvement wherein said crane has a load girt and said equalizer comprises a beam pivotally supported on a pin carried by the load girt of the crane and said equalizer beam is framed in by structural members that will catch and support it in the event said pin fails.
References Cited (Backward Citations)
US1765347A
Cited
US2276767A
Cited
US2306055A
Cited
US2973942A
Cited
US2960310A
Cited
DE1237755B
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-21 | 1977-07-23 | 1978-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-21 | 1981-07-23 | 1982-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-21 | 1985-07-23 | 1986-01-22 | $7700.00 | Window Closed / Lapsed |