US802456A

US802456A - Car-body for wrecking-cranes.

Info

Publication number: US802456A
Application number: US22400704A
Authority: US
Inventors: Samuel L Griswold Knox
Original assignee: Bucyrus Co
Current assignee: Bucyrus Co
Priority date: 1904-09-10
Filing date: 1904-09-10
Publication date: 1905-10-24
Anticipated expiration: 1922-10-24

Description

No. 802,456. PATENTED OCT. 24, 1905.`

S. L. G. KNOX.

GAR BODY FOR WREGKING GRANES.

APPLIUATIUN FILED sBPT.1o.19o4.

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No. 802,456, PATBNTED OCT. 24, 1905. S. L. G. KNGX.

CAR BODY FOR WREGKXNG CRANES.

APPLICATION FILED SEPT.10,1904.

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SAMUEL L. GRISWOLD KNOX, OF MILWAUKEE, IVISCONSIN, ASSIGNOR 'IO THE BUOYRUS COMPANY, OF SOUTH MILWAUKEE, WISCONSIN,

A CORPORATION OF WISCONSIN.

Specification of Letters Patent.

Patented Oct. 24, 1905.

T0 all whom, it 'may ro/tccrn:

. Be it known that I, SAMUEL L. (inswoLn KNOX, a citizen of the United States, residing in the city and county of Milwaukee, State of Wisconsin, have invented certain new and'useful Improvements in Oar-Bodies for Wrecking-Cranes; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appcrtains to make and use the same.

This invention embodies an improved form of structure for supporting' revolving' jibcranes and the like during their operations in lifting and transporting' loads, said structure being' preferably in the form of a car-body mounted upon wheels or trucks to permit it being moved from place to place.

The application has particular reference to that type of railway wrecking-cranes shown and described in United States Letters Patent to Samuel L. Griswold Knox and Walter Ferris, No. 743,889, dated November 10, 1903.

The functions of a wrecking-crane car-body are twofold: iirst, to support its own weig'ht and that of thc superposed revolving jibcrane during transportation, and, secondly, to resist the external strains imposed upon it during the operation of the jib-crane in lifting heavy loads at varying' and relatively long distances from the center of the car. In order to provide stability and enable the crane to lift these overhanging loads, the car is ordinarily provided at its four corners and also midway between its ends with extensible structures known as jack-arms or outrig'gers, which during transit may be folded down or drawn in within the regular lines of clearance of the railway-car. I/Vhen the crane is to lift a heavy load requiring greater stability than is provided by its wheel-base upon the rails, one or more of these outriggers are extended on the side of the crane toward the load to be lifted. Blocking is then placed under the extended outriggers, resting upon the ground, so that the outrigg'ers when the crane is lifting a load form supports or fulcrums by means of which the weight of the car and the crane on one side of the line drawn through the outriggers is caused to overbalance the weight of the load suspended from the crane and projecting on the other side of said line, thus enabling the crane to lift a load substantially equal to the weight of the car and crane without being overturned. VDuring the lifting' of such heavy loads, with the jib extended in the various directions, very heavy strains are transmitted by certain of the outriggers to certain parts of the carbody; and the object of this invention is to provide a structural car-body in which by the peculiar arrangement of its component members a very great economy in material and a large increase in rigidity and ability to resist strains are attained.

In the accompanying' drawings, Figure l is a plan view, partly in section, of a car-body `structure embodying the features of my invention. Fig. 2 is a side elevation, partly in longitudinal section, of the same. Fig. 3 is an end elevation, partly in section, of the carbody, showing' one of the jack-arms or outriggers in operative position.

Referring' to the drawings, t a indicate longitudinal beams forming the sides of the carbody, said beams being' made up of heavy I-beams and-plates, constituting a trussed structure of the type usually employed in cars of this character. These longitudinal beams are connected at their ends by transverse beams I) I), which are preferably in the form of box-girders, as indicated in Figs. 1 and 2.'

I-Ieretofore it has been customary to provide the usual loor-supports for the car-body by placing two or more longitudinal girders or beams in parallel relation between the side beams and connecting the same to the transverse beams or end sills. It has been found in actual practice, however, that this mode of construction does not impart suicient rigidity and. stability to the car-body under heavy lifting loads, and as a result the whole car-body structure has been subjected to severe racking strains, which result in the deformation of the car and the ultimate weakening of the entire structure. This tendency to deformation of the car-body is greatly increased, of course, when the whole load is imposed upon one or more outriggers. For example, if the line m represents the jib extending out over the corner of the car while lifting a heavy load it will be seen that while the load is being lifted a very heavy downward pressure is imposed on the Outrigger at that corner of the car, while a correspondingly heavy upward pull comes upon the cen- IOO ter of the car, which supports the foot of the revolving frame of the jib. Under these circumstances the corner of the car under the load tends to bend downward, while the diagonally opposite corner is lifted and the other corners of the car being' unloaded the tendency is to twist the car-body structure, and as the longitudinal girder construction is not suiiicient to resist this twisting action and to cause the car-body to move as a whole under the lifting strain the framing of the car-body receives a permanent set or deformation which greatly impairs its usefulness, and which if carried too far renders the apparatus carried thereby dangerous and even inoperative. As above indicated, the purpose of the invention is to so construct the carbody that it will be very rigid and capable of resisting great strains without deformation. To this end there are interposed between the side girders and the end girders diagonal cross-girders, which are riveted to the side and end girders, and thereby tie the whole frame of the car-body together as a single rigid structure. In the particular form of the invention illustrated there are provided two intermediate transverse girders c c, which are secured to the opposite side girders a a and serve as a boxing or housing for the center jack-beam p. This latter, which consists of two I-beams rigidly connected by top and bottom plates, rests upon rollers j, supported between the girders c c, so that said jack-beam may be readily run in and out of its housing. In the spaces at the ends of the car formed by the side girders (t, the end girders 7), and the intermediate transverse girders c are applied the sets of cross-girders Z (Z, which constitute substantially the diagonals of thequadrilaterals formed by the respective girders and which are securely riveted thereto by means of angle-plates e e. These cross-girders are preferably formed of rigid I-beams capable of supporting great strains without deformation. Intermediate girders, either longitudinal or transverse, may be employed between the pairs of diagonal cross-girders, the essential point being that the longitudinal and transverse girders constituting the sides and ends of the car-body frame shall be held rigidly parallel with each other by the crosses so placed as to transmit strains from one girder to another, as hereinafter explained. At each corner of the car there is mounted a jack-arm or Outrigger q, adapted to swing outward in a vertical plane from the car-body, for which purpose each jack-arm is pivoted to the car-body in the manner illustrated in Figs. 2 and 8. This mode of supporting the jack-arms also permits the latter to be folded back when out of use, so as to lie within the planes of the car sides. f

Supported on the center of the car-body is a circular traclrway It', upon which the revolving jib structure is mounted, said tracliway being provided with annular projecting top and bottom fianges im, which coperate with bearing-rollers n, `n` n o in a manner particu` larly described in the patent above referred to. In order to effectually support the circular tracliway and the jib structure carried thereby and centered by the bearing t', short transverse gird ers ff are interposed between whereby a general octagonal foundation is formed by sections of the side girders a, the ends of the crossgirders CZ, and said transverse girders f, which foundation underlies the entire base of the traclrway-casting and distributes the weight thereof, with that of the jib and the load, to all of the members of the car-bod y frame.

To illustrate the disposition of the forces imposed upon the frame of the car-body by a heavy load lifted by the jib, let it be assumed that the jib is in the position indicated by line fr ne, in which the end of the jib extends out over the corner of the car while lifting a heavy load. In this position of the jib a very heavy downward pressure is produced upon the two front rollers n 0, which support the revolving frame upon the circular track 71: at the end of the said revolving frame toward the jib, while a heavy upward pull is imposed upon the rollers n n at the end of the revolving frame away from the jib, as particularly pointed out in the patent above referred to. Acting through the circular track 7c these rollers exert a heavy downward strain upon one portion Hof the carbody and heavy upward strains upon another portion thereof.

It may be noted that in the relation of the various parts of the mechanism indicated in Fig. l the distance from the center of the car-body to the blocking under the Outrigger p is approximately ten feet, while the load supported by the crane is situated about ten feet beyond the Outrigger or substantially twenty feet from the center of the car. Under these conditions it is evident that the crane may lift approximately its own weight without being overturned, provided that the center of gravity of the crane is approximately coincident with the center of the car. The Outrigger q, situated between the center of the crane and the load, serves as a fulcrum or support, acting upon which the weight of the crane must overbalance the weight of the load. If the total weight of the crane be eighty tons,which is approximately that of ordinary railway practice, a load of nearly eighty tons can be lifted by the crane in the position shown, and almost the total weight of both'crane and load, or one hundred and sixty tons, will be resting upon this single Outrigger attached to the corner of the car. This illustrates the enormous local and eccentric strains which the car-body is designed to resist. In the opera- I tion of lifting a load in this position at least 1 three outriggers should be extended-namely,

adjacent members of the cross-girders (Z,

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spaae the jack-beam p and the two jack-arms ql] at the end of the car which the load .overhangs Disregarding the supporting eilects of the truck upon the track as a comparatively negligible element, it will be seen that the load will be supported by these three outriggers. It' the jib extends over the center of one corner-outrigger q, as indicated in Fig. 1, we may assume that no load is taken up by either of the other outriggers or by the truck. Under these circumstances, with the crane lifting its maximum load, assumed at one hundred and sixty thousand pounds, there will be an upward pressure ot' three hundred and twenty thousand pounds under the foot of this corner-Outrigger, and this upward pressure, with the downward pressure on the two liront rollers 0 o and the upward pressure of the two rear rollers a n, acts directly upon the car-body, which must be sufficiently rigid throughout to resist these various heavy strains and hold the entire system in equilibrium. rIhe diagonal cross-girders, which are rigid and inflexible under even a load of this character, transmit the strains to all parts of the car-body framing and prevent any deiiection or deformation thereof, as the entire framing is thereby caused to move as a unit and the various members thereof are prevented from twisting out of the normal plane of the structure.

Having thus described my invention, what I claim is- 1. A car-body for wrecking-cranes and the like, comprising parallel longitudinal girders, end and intermediate transverse girders connected thereto, and diagonal cross-girders secured to the longitudinal and transverse girders and lying within the rectangular frame formed by said longitudinal and transverse girders.

2. A car-body for wrecking-cranes and the l like, comprising parallel longitudinal girders,

transverse end girders connected thereto, and diagonal cross-girders secured to the longitudinal and transverse girders and lying within the rectangular frame formed by said longi* tudinal and transverse girders.

3. In a swinging-structure wrecking-crane, a car-body comprising parallel longitudinal girders. transverse end girders connected thereto, diagonal cross-girders secured to the longitudinal and transverse girders, and a circular trackway for the swinging structure supported on thelongitudinal and cross girders.

4L. In a swinging-structure wrecking-crane, a car-body comprising' parallel longitudinal girders, transverse end girders connected thereto, one or more intermediate transverse girders between the respective longitudinals, diagonal cross-girders secured to the longitudinal and transverse girders, and a circular trackway for the swinging structure supported on the longitudinal and cross girders.

5. In a swinging-structure wrecking-crane, a car-body comprising parallel longitudinal girders, transverse end girders connected thereto, two intermediate transverse girders between the longitudinal girders forming a boxing for the center Outrigger, and diagonal cross-girders between the longitudinal and transverse girders.

6. In a swinging-structure wrecking-crane, a car-body comprising parallel longitudinal girders, transverse end girders connected thereto, two intermediate transverse girders between the transverse girders forming a boxing for the center Outrigger, diagonal crossgirders between the longitudinal and transverse girders, and a circular traclway for the swinging structure supported on the longitudinal girders and the adjacent sections of the cross-girders.

In testimony whereof I aflix my signature in presence of two witnesses.

SAMUEL L. GRISWOLI) KNOX. Witnesses:

HARRY B. HAYDEN, P. C. Bonn.