US2997005A

US2997005A - Overhead crane frame or bridge

Info

Publication number: US2997005A
Application number: US3593A
Authority: US
Inventors: Jr William S Chapin; Erhard H Steins
Original assignee: Manning Maxwell and Moore Inc
Current assignee: Manning Maxwell and Moore Inc
Priority date: 1960-01-20
Filing date: 1960-01-20
Publication date: 1961-08-22
Anticipated expiration: 1978-08-22

Description

1961 w. s. CHAPlN, JR., ET Al. 2,997,005

OVERHEAD CRANE FRAME OR BRIDGE 4 Sheets-Sheet 1 Filed Jan. 20, 1960 JHI EHJUPE William S. (la/in In E r/Laral I! .5122 1. n6

g- 1961 w. s. CHAPIN, JR ETAI. 2,997,005

OVERHEAD CRANE FRAME OR BRIDGE Filed Jan. 20, 1960 4 Sheets-Sheet 2 fnyenfar's Mil 1 11am .5. Cfie a'n J'r: Erhard H Steins ZMNW l 5.

Aug. 22, 1961 w. s. CHAPIN, JR.. ETAI. 2,997,005

OVERHEAD CRANE FRAME OR BRIDGE Filed Jan. 20, 1960 4 Sheets-Sheet 3 William iffla n'n Jr Erhard H. Steins 1961 w. s. CHAPIN, JR ET Al. 2,997,005

OVERHEAD CRANE FRAME OR BRIDGE 4 Sheets-Sheet 4 Filed Jan. 20, 1960 KW i a I h I I H H H H I I I M WM Wm fZYZ E'HZUFE W/lt'am 5 (kqaz'n In Erhard f1. Steins 2,997,005 OVERHEAD CRANE FRAME OR BRIDGE William S. Chapin, Jr., Spring Lake Township, Muskegon County, and Erhard H. Steins, Norton Township, Muskegon County, Mich., assignors to Manning, Maxwell & Moore Incorporated, Muskegon, Mich., a corporation of New Jersey Filed Jan. 20, 1960, Ser. No. 3,593 10 Claims. (Cl. 105-163) This invention relates to improvements in overhead crane frames or bridges, and more particularly to the main bridge or frame construction for overhead cranes of the heavy duty type, the invention being particularly desirable for use in connection with cranes of the type of ladle cranes, wherein there are separate trolleys carrying separate hoisting means supported entirely by the crane bridge which is in itself a trolley carrying the full load on the hoisting mechanisms as well as the load of the crane itself, although the invention will have other uses and purposes as will be apparent to one skilled in the art.

Overhead cranes, particularly those of the larger type, most commonly embody a bridge supported on trucks movable along tracks carried by runway beams supported on columns which may be independent of, attached to, or integral with the building columns. This main frame supports the entire weight of the overhead crane plus all the loads that may be connected to the hoisting means associated therewith. Some overhead cranes, particularly ladle cranes of the type used in foundries for the pouring and transporting of molten metal, ingots, castings, and the like, embody dual trolleys each equipped with hoisting apparatus. Such a crane would embody a main frame having opposed parallel end tie members, a pair of main girders therebetween to support track means for the trolley carrying the main hoist, and a secondary pair of girders between the end tie members having track means for supporting the trolley carrying the lighter load hoist mechanism. When it is considered that the load upon the main hoist trolley may exceed 200 tons, while that upon the auxiliary trolley may run between and 50 tons, it will be apparent at once that there is considerable stress on the frame and the deflection of the secondary girders is not the same as the deflection of the main griders.

Heretofore, all girders and end tie members have been connected rigidly together by bolting, riveting, welding, or in an equivalent manner, whereby the main frame was a single rigid structure. Consequently, deflection in the secondary girders, differing from that in the main girders, caused a tremendous load on the rigid connections between the secondary girders and the end tie members. Such deflection causes the ends of the secondary girders to tend to assume a slightly angular position relatively to the end tie members, and the tie members are prevented from assuming any slightly angular position by means of the rigid connections with the main girders. The unfortunate result was that failures occurred at the connections between the secondary girders and the end tie members.

Since the end tie members are held in upright position solely by the rigid connections with the main girders, such problem did not exist with cranes having only one pair of girders connected to the end tie members, because those end tie members were free to assume the same angularity as that of the ends of the main girders, but the difficulty of stress concentration resulting in failures occurred when more than one pair of girders were rigidly connected to the end tie members.

Accordingly, it is an important object of this invention to provide a main frame or bridge for an overhead rates atent Patented Aug. 22, 1961 crane that overcomes the objections above noted to the structure utilized heretofore.

It is another important object of this invention to provide an overhead crane having a main frame or bridge with two pair of girders connected to end tie members, one pair being rigidly connected to the end tie members, and an articulate connection being provided between the ends of the other pair of girders and the end tie members,

It is also an object of this invention to provide an overhead crane having a main frame embodying more than one pair of girders connected to the end tie members, one pair of the girders being rigidly connected to the tie members, while the remaining girders are connected to the end tie members in a manner to permit relative movement between the girder ends and the tie members.

Still another feature of the invention resides in the provision of an overhead crane having a main frame embodying end tie members and a plurality of girders extending between and transversely to the end tie members, there being an articulate connection between the ends of at least some of the girders and the end tie members.

It is also an object of this invention to provide an overhead crane having a main frame with a pair of load supporting girders connected rigidly to the end tie members, and another pair of girders for supporting a load of a different amount connected to the end tic members in a manner to permit relative pivotal movement of the girders with respect to the end tie members.

Also a feature of this invention is the provision of an overhead crane having a main frame in which channel brackets are provided on the end tie members, and at least one pair of girders extending between those end tie members are seated within the channel brackets, there being means extending across the brackets beneath the girder ends to support the girders.

While some of the more salient features, characteristics and advantages of the instant invention have been above pointed out, others will become apparent from the following disclosures, taken in conjunction with the accompanying drawings, in Which FIGURE 1 is a fragmentary side elevational view of an overhead crane embodying principles of the instant invention, with parts broken away and parts shown in section;

FIGURE 2 is a fragmentary end view of the structure seen in FIGURE 1, taken from the righthand side of FIGURE 1;

FIGURE 3 is a diagrammatic top plan view of the main frame structure of the crane, with all parts thereabove removed for purposes of clarity;

FIGURE 4 is an enlarged fragmentary end view of the main frame, some parts being shown diagrammatically;

FIGURE 5 is an enlarged fragmentary vertical sectional view, taken substantially as seen by the line VV of FIGURE 3, looking in the direction of the arrows;

FIGURE 6 is a reduced fragmentary vertical sectional view, taken substantially in the same location as FIGURE will also be appreciated that where reference is made to end tie members, girders, and the like, these are not usually formed of one piece of material, but are fabricated of metal plates and slabs, riveted, bolted, or welded together in a known manner to provide a girder or the like of suitable size and strength for the intended purpose, and the fabrication of all of the parts of such girders will not be herein specifically set forth.

The illustrated embodiment of the overhead crane embodies a bridge .or main frame, generally indicated by numeral 1, which carries the entire crane load. Each corner of the main frame 1 is supported by a truck 2 having a plurality of wheels 3 thereon, in the illustrated instance there being four such wheels on each of the four trucks. The trucks are designed to move on track rails 4-4 which may be supported, as diagrammatically indicated at 5--5 in FIGURE 1, on runway beams supported on columns which may be independent of, attached to, or integral with the building columns.

It will therefore be apparent that the bridge with the trucks 2 constitutes an immense trolley, and carried by suitable framework of a known type, suspended from this trolley, is a suitable control room 6 as seen in FIG- URE 2, a number of flights of stairs 7, various platforms as indicated at 8, catwalks as indicated at 9, upstanding handrails at 10, lights 11, as well as all of the various motors and equipment necessary to operate the entire crane structure.

Ridable upon a track formed by rails 1212 carried by portions of the main frame 1 to be later described, is a light capacity trolley 13. This trolley 13 carries suitable motors and hoisting mechanism, diagrammatically indicated at 14 and 15, from which a pair of load hooks 16 and 17 depend on suitable chains or ropes. These hooks are for relatively light loads, and by way of example and not by way of limitation, the hook 16 might carry a load of 40 tons while the hook 17 would pick up a load of approximately 5 tons.

At a higher level on the main frame 1 is another wider track formed by rails 18-18 on which a heavy capacity trolley 19 may travel. This trolley carries suitable heavy duty motors 202tl and hoisting drums 2121 from each of which a hook 22 depends on suitable lifting chains or ropes, one of these hooks being seen in FIG- URE 1. When the crane is used to handle ladles of molten metal, the two hooks 22 take a ladle from opposite sides and carry it along to the pouring location, when one of the smaller hooks on the trolley 13 may be utilized to tip the ladle and pour at the proper location. This higher trolley 19 may carry a load reaching into several hundred tons.

Now with reference more particularly to FIGURES 3, 4 and 5, it will be seen that the frame 1 comprises a pair of opposed parallel and like end tie members 2323 each of which is connected with one of the aforesaid trucks 2 at each end thereof. These end tie members 2323 are in the form of large heavy fabricated beams, but for purposes of convenience herein will be referred to as they are in manufacturing practice as end tie members.

Extending between and transversely to the end tie members 23-43 is a pair of spaced main girders 24-24. These girders support the rails 18-18 forming the track for the upper heavy capacity trolley 19. The two main girders 2424 are rigidly secured to the end tie members as by belts or rivets 25 seen in FIGURE 4. The end tie members 23-23 are maintained in upright position by this rigid securement thereto of the ends of the main girders 2 3-24. Consequently, any deflection of the main girders 2424 due to the load thereon will cause no trouble, since the end ties 23-23 may tip from the vertical and follow along with such deflection.

However, in the present instance, for carrying the tracks formed by rails 1212 for the light capacity trolley 13, secondary girders 2626 are provided. Should these girders 2626 be rigidly connected to the end ties 23-23 as well as the main girders 24-24, failure would possibly occur at the connections between the ends of the secondary girders and the end tie members. This would be due to the fact that the secondary girders carry a different load than the main girders and are therefore subject to different conditions of possible deflection. But the end tie members being held by the main girders cannot respond to a deflection of the secondary girders because they are prevented from so doing by the main girders. Assuming, for example with rigid connections between the secondary girders and the end ties, that the secondary girders are carrying a full load while the main girders are carrying substantially no load, the secondary girders have a tendency for the end portions thereof to assume a slight angle with respect to the end tie members, thereby setting up a terrific concentration of stresses at the connections with the end tie members. In the past, failures frequently resulted at those connection points.

To overcome such a situation, the instant invention provides What may conveniently be termed an articulate connection between each end of each secondary girder and the respective end tie mmber; i.e., a connection that permits a relative movement between the end of a secondary girder and the end tie membr, thereby permitting the secondary girders to deflect under load, and no additional stress is applied to the connections between the secondary girders and end tie members regardless of what load may be on the main girders.

Various forms of articulate connections between the secondary girders and the end tie members may be utilized, two modifications being set forth herein. The first and preferred form of such connection is best seen in FIG-

URES

3 and 5. As stated above, the secondary girders 26-26 are at a lower level with respect to the end tie members than the main girders 2424. To accomplish this, the end tie members are each provided with a recess 27 therein as best seen in FIGURE 3, and the secondary girders are secured to the end tie members adjacent the bottom of that recess, whereby the rails 1212 may extend beyond the secondary girders into the recess of the end tie members.

Adjacent each end of each secondary girder, the respective end tie member has secured thereto a channel shaped bracket 28, the base of which is rigidly affixed to the end tie member, and the arms of which extend parallel with the secondary girder. Each arm is provided with reinforcing wings as indicated at 29 on the outer sides thereof. The end of the secondary girder extends between the arms of a bracket, and through the bracket arms and girder end a pivot pin 30 is mounted, this pin being held in position by a key 31 secured to one of the bracket arms. The pivot pin supports the end of the secondary girder, and as a safety factor, a shelf 32 is preferably provided between the arms of the bracket a slight distance below the bottom of the end of the secondary beam, as seen best in FIGURE 5. Such shelf will support the end of the secondary girder in the event of failure of the pivot pin for any reason.

It will be seen, therefore, that the pivot pins supporting the ends of the secondary girders readily permit a deflection of those girders and a tipping of the ends of the girders relatively to the end tie members without any additional stress being imposed upon the connection between the secondary girders and end tie members. Consequently, there should be no failures at the points of connection regardless of the different loads carried by the trolleys on the main and secondary girders.

In FIGURES 6 and 7, we have illustrated a different form of articulate connection between the end of a secondary girder and an end tie member. In this instance, a bracket 33 is secured to the end tie member 23, this bracket being of channel shape but having a bottom 34 between the arms thereof, with suitable bracing ribs 35 underneath the bottom. The end of a secondary girder 26 merely seats in the socket formed by the bracket and ass'aoos rests upon the cross member or bottom 34, no securing means being utilized. Since the end tie members are held in proper spacing by the main girders 24-24, there is no opportunity for the secondary girders to slip out of the socket brackets 33. Resting upon the bracket bottom or shelf 34, each secondary girder is free to assume a slight deflection, with the tendency of the girder end to be disposed at a slight angle to the vertical wall of the end tie member. No additional stress will be imposed on the connection between the secondary girder and the end tie member regardless of the relative loads carried by the trolleys 13 and 19.

From the foregoing, it will be apparent that we have provided an overhead crane having an excess of one pair of girders extending between the end tie members of the main frame, and yet there is no additional or undue stress imposed upon the connections between the ends of the girders and the end tie members, by virtue of the articulate connections supplied between all but the main girders and the end tie members. The construction is extremely long lived, highly durable, and eliminates the possibility of failures to a considerable extent.

It will be understood that modifications and variations may be eifected without departing from the scope of the novel concepts of the present invention.

We claim as our invention:

1. In the bridge or main frame for an overhead crane, a pair of opposed parallel end tie members, a pair of main girders between said end tie members and with their ends rigidly connected to said end tie members, a pair of secondary girders between said end tie members, and an articulated connection between the respective end tie member and each end of said secondary girders.

2. In the main frame for a heavy duty overhead crane, a pair of parallel end tie members, a pair of load bearing main girders between said end tie members, a pair of load bearing secondary girders between said end tie members, a connection at each end of one of said pairs of load bearing girders and the respective end tie members permitting relative movement therebetween, and the other pair of load bearing girders being rigidly connected to the end tie members.

3. In the main frame of an overhead crane, a pair of opposed parallel end tie members, a plurality of pairs of load bearing girders extending between and transversely to said end tie members, articulated connecting means between the end tie members and certain of said pairs of load bearing girders, and the remaining load bearing girders being rigidly connected to said end tie members.

4. In the main frame of an overhead crane, a pair of opposed parallel end tie members, a pair of main girders extending between and transversely to said end tie members and with the ends thereof rigidly secured to the respective end tie members, track means on said girders to support a heavy load bearing trolley, a pair of secondary girders extending between and transversely to said end tie members, connecting means between the ends of said secondary girders and the respective end tie members permitting relative pivotal movement between the girder ends and the end tie members, and track means on said secondary girders to support a lesser load bearing trolley.

5. In the main frame of an overhead crane, end tie members, a pair of main girders extending between and transversely to said end tie members and having their ends rigidly connected to said end tie members, a pair of secondary girders extending between and transversely to said end tie members, a bracket on said end tie members adjacent each end of the secondary girders, and means pivotally connecting the ends of said secondary girders to said brackets.

6. In the main frame of an overhead crane, end tie 6 members, a pair of main girders extending between and transversely to said end tie members and having their ends rigidly connected to said end tie members, a pair of secondary girders extending between and transversely to said end tie members, a channel shaped bracket on said end tie members adjacent each end of said secondary girders, and each end of said secondary girders being disposed in the channel of one of said brackets to permit relative movement between the ends of the secondary girders and said end tie members.

7. In the main frame of an overhead crane, end tie members, a pair of main girders extending between and transversely to said end tie members and having their ends rigidly connected to said end tie members, a pair of secondary girders extending between and transversely to said end tie members, brackets on said end tie members adjacent the ends of said secondary girders, spaced arms on each bracket extending perpendicular to said end tie members, each end of a secondary girder being disposed between the arms of a bracket for pivotal movement relatively thereto, and a cross member between the arms of each bracket beneath the respective end of a secondary girder.

8. In the main frame of an overhead crane, end tie members, a pair of main girders extending between and transversely to said end tie members and having their ends rigidly connected to said end tie members, a pair of secondary girders extending between and transversely to said end tie members, brackets on said end tie members adjacent the ends of said secondary girders, spaced arms on each bracket extending perpendicular to said end tie members, a cross member between the arms of each said bracket, and each end of a secondary girder resting loosely on a bracket cross member between the bracket arms and spaced from the respective end tie member.

9. In the main frame of an overhead crane, end tie members, a pair of main girders extending between and tranversely to said end tie members and having their ends rigidly connected to said end tie members, a pair of secondary girders extending between and tranversely to said end tie members, brackets on said end tie members adjacent the ends of said secondary girders, spaced arms on each bracket extending perpendicular to said end tie members, each end of a secondary girder being disposed be tween the arms of a bracket and spaced from the respective end tie member, and a pivot pin passing through the bracket arms and girder end therebetween.

10. In the main frame of an overhead crane, end tie members, a pair of main girders extending between and transversely to said end tie members and having their ends rigidly connected to said end tie members, a pair of secondary girders extending between and transversely to said end tie members, brackets on said end tie mem bers adjacent the ends of said secondary girders, spaced arms on each bracket extending perpendicular to said end tie members, each end of a secondary girder being disposed between the arms of a bracket and spaced from the respective end tie member, a pivot pin passing through the bracket arms and girder end therebetween, and a lateral shelf between the arms on each bracket below the end of the respective secondary girder to support the same in the event of failure of the pivot pin.

References Cited in the file of this patent UNITED STATES PATENTS Re. 22,905 Scheyer Aug. 12, 1947 495,783 Cavallaro Apr. 18, 1893 944,054 Sawyer Dec. 21, 1909 1,662,197 Macomber Mar. 13, 1928 1,662,768 Wait Mar. 13, 1928 2,260,317 Harry Oct. 28, 1941