US2602551A

US2602551A - Micrometric control for boom hoisting means

Info

Publication number: US2602551A
Application number: US88746A
Authority: US
Inventors: Fred L White
Original assignee: OSGOOD Co
Current assignee: OSGOOD Co
Priority date: 1949-04-21
Filing date: 1949-04-21
Publication date: 1952-07-08
Anticipated expiration: 1969-07-08

Description

y 1952 F. L. WHITE 2,602,551

MICROMETRIC CONTROL FOR BOOM HOISTING MEANS Filed April 21, 1949 3 Sheets-Sheet 1 FIG. 5.

13 13 Z/ 1' w b l 29 INVENTOR. FRED l WHITE FIG. I. Z9 24-" BY ATTORNEY F. L. WH |T MICROMETRIC CONTROL FOR BOOM HOISTING MEANS Filed April 21, 1949 3 Sheets-sh 2 &

nmmmuuum mvamoa; FRED L. WHITE RNEY.

y 1952 F. WHITE MICROMETRIC CONTROL FOR BOOM HOISTING MEANS 3 Sheets-Sheet 3 Filed April 21. 1949 HV/R v lli FIG. 4.

INVENTORZ FRED L WHITE ATTORNEY.

Patented July 8, 1 952 Mro'aoME'rRIo ooN'rRoL FOR/BOOM.

HOISTING MEANS Fred L. White, Marion, Ohio, assignor to The Osgood Company, Marion, Ohio, a corporation of Ohio Application April 21, 1949, Serial No. 88,746

8Claims. (c1. sin-59) V This invention relates to portable self-propelled hoisting equipment and is more particularly directed to a hoisting means for the boom whereby the unpivoted end of the boom may be accurately and minutely moved from one vertical position to another. J p V The object of this invention is to provide a hoisting means for the longitudinally extended boom on a hoisting device so that its unpivoted end can be moved between two given radial positions and in small degrees of movement with a very high degree of precision and accuracy.

Another object of the invention is to provide a means for controlling the radially outward position of the unpivoted end of a longitudinally extended boom which comprises a cable reeving means and a pressure fluid motor unitand in which the former controls'the booms major vertical movements for its unpivoted end and in which the pressure fluid motor unit controls the booms smaller vertical movements for its unpivoted end. f

Another object of the invention is to provide a means for moving the unpivoted end of a boom for ahoisting machine in which a cable reeving meanslcontr'ols the larger movements thereof and in which the smaller precision movements of the unpivoted end are controlled by a pressure fluid operated means that operates in connection with the cable reeving means.

The invention primarily consists of a boom that is pivoted to a suitable supporting member and means on the latter for supporting the hoisting means for the unpivoted end of the boom. This hoisting means includes a cable reeving device by means of which the unpivoted end of the boom is moved through the larger ranges of movement. Pressure fluid operated means controlled by a three way throttle valve is associated with the cablereeving means for moving the unpivoted end of theboom through the small, accurate and precise ranges of movement whereby loads suspended from a load supporting hook and its cable can be accurately and precisely located with no danger of having the load slip positionancl all under the complete control of the operator.

In the drawings: I

Fig. 1 is a side elevational view of a hoist incorporating the invention;

Fig. 2 is an enlarged side elevational view of the gantry and the parts supported thereby;

Fig. 3 is a front elevational view of the gantry illustrated in Fig. 2 with parts omitted to show detail;' 3 g Fig. 41s a rear elevational view of the gantry illustrated in Fig. 2 with parts omitted to show detail; and 1 Fig. 5 is a view of a part of the cable and sheaves shown inFig. 1 looking in the direction (if the line 55. p I I The invention'is incorporated in a hoisting mechanism illustrated in the several views of the drawing in which I is an upper body of a portable self-propelled hoist that is rotatably mounted on a suitable chassis 2 which includes endless track type traction members and a suitable prime mover and controls therefor may be provided (not shown) in the upper body asis customary in the art. v V

A. boom 3 is pivotally supported on theupper body I in a conventional manner. This boom has a length much greater than those on ordinary hoists and frequently has a length of ninety feet or more. This is the type of mechanism used on hoists employed in construction work for raising beams or other structural members and then accurately locating them in'the desired position. A hoisting means, shown in dotted lines, is mounted on the upper body from which a cable 3 extends to the upper end of the boom where it is threaded over a suitable sheave (not shown) and a grab hook is usually provided on the end of the cable to which loads may be secured all of which is arranged as is well understood in the art.

A gantry is'mounted on the upper body which is made to extend an appreciable distance above the cab comprising a part of said upper body. The gantry comprises a pair of uprights 4, normally supporting some of the hoist operating mechanism, secured to'frame 5 constituting the platform or deck for the upper body I. A pair of

gantry legs

6, 6 is connected'to brackets 6' with one of the legs being secured to each bracket. The upper end of the gantry legs 6 are secured to a bar '1 with the legs positioned at the opposite ends of said bar; A pair of back legs '8, 8 made up of two angularly related parts extend betweefi the I bar 1 and the frame 5, the lower end of the back legs 8 being secured to the frame 5 by pins l0 suitably disposed in brackets provided on said frame. A bar 9 isconnected between the upper end of the uprights 4 and it also extends through enlargements on the back legs 8. The gantry; is therefore a rigid sturdy structure for supporting the unpivoted end of the boom 3.

Hoisting means for the unpivoted end/of the boom are connected between said end of the boom 3 and the upper end of the gantry, one part of which comprises a pair of pressure fluid operated motors ll, Hone end of each motor being pivled to a sheave l8 rotatably mounted on a jack shaft 20, then is led downwardly and passed around sheaves I3, then upwardly and around sheave l9 rotatably supported on the jack shaft and is then led down to the shackle bar [2 where it is secured to an anchor 21 connected thereto. A cable 22 is connected between the ends of jack shaft 20 and the unpivoted end of the boom 3. The latter cable completes the connecting link between the unpivoted end of the boom and the gantry. The unpivoted end of the boom is raised and lowered by reeving and unreeving the cable M on the drum l5 and by the operation of the fluid motors ll.

The fluid motors II are operated by pressure fluid derived from a pump 23 which draws fluid from a tank 24. Conduit 25 conducts pressure fluid to three way valve 2 6 acting as a reversing and throttle valve, and from said valve fluid is conducted to one end of each of the motors l l by conduit 21. Fluid is conducted to and from the other end of the motors II by conduit 28 which also connects to the valve 25 and conduit 29 is a return passageway connected between the valve and the tank 24. Valve 26 is adjusted by handle 30 so that fluid can be directed to either end of the motors l I. I

the drum l5 and because cable [4 will not reeve uniformly thereon the boom may drop a considerable distance because of cable slippage while being wound and unwound. The fluid motors are actuated for accomplishing small adjustments in elevation of the boom which can be accurately controlled by the three way or reversing valve 26.

Assume that a boom ninety feet in length is connected to the frame 5 of the portable hoist. With the cable organization disclosed which is customary in the art it will be necessary to reeve and unreeve' from the drum !5 twelve feet of cable to change theoperating radius of the boom from twenty to forty feet. When the boom radius moves between the same distances by means of the fluid motors they need only move four feet,

therefore a comparatively short motor action will move the boom the same distance in a much shorterspace of time and requiring shorter travel distance of the actuating means. The latter mo -.tion or that of" the motors H, H is performed rapidly and accurately and can be done in very small precise amounts, tantamount to micro- -metric accuracy. When the fluid motors are hook hoist. 'The cable tends to pile up on the relatively narrow drum and frequently slips when piled thus permitting the unpivoted end of the boom to drop as much as several inches thereby endangering personnel and any load that may be carried by the grab hook. The instant invention obviates these disadvantages and in addition provides the very reliable and desirable result that a load may be positioned with extreme accuracy. Also, the unpivoted end of the .boom

-may be selectively controlled by a simple extensible fluid motor and assuming that it has a ,four foot stroke its motion may change the effective boom operating radius twenty feet, rapidly and safely, and may be changed slop/1y with extreme precision. Changes in boom length will produce proportionate changes in movements and by changing the operating ranges of the fluid motors corresponding changes in effective boom radius can be made.

The foregoing mechanism provides an effective means for making major changes in boom elevation with the cable reeving mechanism and micrometric changes in boom elevation, and therefore grab hook elevations, with the fluid motor portion of the boom hoisting mechanism.

That which is regarded new, novel and useful and which is sought to be protected by Letters Patent of the United States is as follows:

1. A hoist comprising a frame; a boom, one end of which is pivoted to said frame, its other end being unpivoted; a gantry on said frame; means extending between said gantry and the unpivoted end of said boom including aserially connected cable and a piston-cylinder type of pressure fluid operated means; means for reeving said cable for moving the unpivoted end through large vertical adjustments; and means for actuating said pressure fluid operated means for moving the unpivoted end vof said boom through minor vertical adjustments.

2. A hoist comprising a frame; a boom; means for pivoting one end of said boom to said frame, the other end of said boom being unpivoted; a gantry on said frame; piston-cylinder type pressure fluid means. connected to said gantry; cable means connected in series with said pressure fluid operated means, the cable being operative on the unpivoted end of said boom, said cable including a portion divided into a number of strands; means for winding and unwinding said portion of said cable for moving the unpivoted end of said boom for making large vertical adjustments thereof; and means for operating said pressure fluid means for moving the unpivoted end of said boom for making small vertical adjustments thereof.

'in end to'end relation with said cable means;

means for reeling and unreeling said cable means for moving the unpivoted end of the boom large distances; and means for operating said pressure fluid operated means for moving the unpivoted end of said boom small distances.

4. A hoist comprising acable means connectable to the unpivoted end of a boom; a shackle bar; means for associating said cable means with said bar; extensible pressure fluid operated means connectable to said shackle bar and serially connected to said cable means; meansjfor actuating a portion of said cable means for imposing large movements on said boomend; and means for actuating said pressure fluid means for imposing small movements on said boom end. 1f.

5. A hoist comprising a frame; a boom; means for pivoting one end of said boom to said frame, the other end of said boom being unpivoted; a gantry mounted on said frame; a pair of extensible pressure fluid'motors connected to said gantry; a shackle bar connected to said pressure I fluid motors; a jack shaft; a cable connected between the unpivoted end of said boom and said jack shaft and connected in series with said pressure fluid motors; cable means connected between said jack shaft and said shackle bar and serially connected with said pressure fluid motors; means for actuating said last mentioned cable means for moving the unpivoted end of said boom through large degrees of adjustment; and means for actuating said pressure fluid motors for moving the unpivoted end of said boom through small adjustments.

6. A hoist comprising a frame; a boom; means for pivoting one end of said boom to said frame,

the other end of said boom being unpivoted; a

gantry mounted on said frame; pressure fluid mo-v between the unpivoted end of said boom and said gantryincluding multiple strand cable means and an extensible pressure fluid operated means in serial relation; and means for actuating said pressure fluid means for moving the unpivoted end of said boom limited distances.

8, A hoist comprising a frame; a boom; means for pivoting one end of said boom to said frame,

' the other end of said boom being unpivoted; a

tor means connected to said gantry; cable means including a multiple strand cable means connected between said pressure fluid motor means and the unpivoted end of said boom in serial relation therewith; means for actuating said multiple strand cable means for making large vertical adjustments of the unpivoted end of the boom; and means for operating said pressure fluid motor means for making small vertical adjustments of the unpivoted end of the boom.

7. A hoist comprising a frame; a boom; means for pivoting one end of said boom to said frame; a gantry on said frame; and means connected gantry on said frame; means connected between said gantry and the unpivoted end of said boom which includes cable means and an extensible pressure fluid motor means in serial relation therewith; means for operating said cable means for moving the unpivoted end of said boom large distances; and means for actuating and controlling said pressure fluid motor means for moving the unpivoted end of said boom small distances. FRED'L. WHITE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 710,472 Lake Oct. 7, 1902 860,761 McCullough July 23, 1907 1,198,833 Galvin Sept. 19,1916

2,139,960 Kauffman Dec. 13, 1938 2,168,128 Kervarrec Aug. 1, 1939 2,433,598 Chadwick Dec. 30, 1947 2,475,963 Howell July 12,1949

Huston Aug. 23,