US1598273A - Traveling crane - Google Patents

Description

Aug. 31, 192d 1,598,273

' B. F. FITCH TRAVELING CRANE Filed Jan- 5, 1925 3 Sheets-sheaf anvcmtoz aw, fl @141 B. F. F ETCH TRAVELING CRANE Filed Jan. 5, 1925 3 Sheets-Sheet 2 muom roa gkm M /M (than my Aug. 31, 1926. 1,598,273

B. F. FITCH TRAVELING CRANE:

Filed Jan. 5 1925 3 Sheets-Shet 5 x i 4 33 v Rel y Z1 (,L m

Patented Aug. 31, 1926.

BENJAMIN F. FITCH, OF GREENWICI-I, CONNECTICUT.

TRAVELING CRANE.

Application filed. January 5, 1925.

This invention relates to a mechanism for skewing or lifting a load which is suspended from a crane, and is concerned primarily with improvements in U. S. Patent No. 1,437,967 issued to me December 5, 1922.

Briefly, the mechanism illustrated in my patent embodies a frame which is arranged to travel on an overhead trackway with hoisting mechanism including drums and cables carried thereby. The cables are illustrated as passing over sheaves which are disposed adjacent the corners of a theoretic rectangle. Two of the sheaves are shiftable axially, wherefore, one end of a load suspended from the cables may be skewed with reference to the crane in order to position the load more accurately with reference to a truck. One of the objections to the use of mechanism which moves the sheaves in a straight line is the fact that one end of the load is raised slightly due to the shifting operation. Accordingly, if hand poweris employed for the skewing operation, then considerable force must be exerted to effect the shifting operation.

The principal object of the present invention therefore, is the provision of mechanism which enables the load to be skewed without requiring it to be moved vertically during the twisting operation. An advantage of this construction is that the mechanism employed for shifting the load need only be sufliciently strong to overcome frietion due to lateral movement of the sheaves with reference to the supporting frame.

I carry out the above object by employing sheaves which are shiftable laterally with reference to the frame being preferably mounted in roller carriages, and by utilizing curved trackways for supporting two of the sheaves. In addition, I arrange mechanism for moving such sheaves simultaneously whereby one end of a suspended load is shifted with reference to the frame. By making the trackways upon the arc of a circle, then each shiftable sheave can be moved without raising'one end of the load. ,The arcuate path in which each sheave moves is determined by the relative position of the movable sheave to other sheaves which are employed for guiding the cables along the frame.

Preferred means for carrying out my in vention is fully set forth in the following description which relates to the accompanying drawings, wherein Fig. 1 is a plan view Serial No. 535.

of a crane embodying my invention; Figs. 2, 3, 4 and 5 are sections taken on the correspondingly numbered lines in Fig. 1, and Fig. 6 is a section taken on the line 66 in Fig. 5; Fig. 7 is a detail View illustarting a safety device for the screw and nut couple; Fig. 8 is a section taken transversely through the couple shown in Fig. 7.

My invention is shown in connection with an overhead hoisting mechanism which is employed for engaging, raising and transporting removable automobile bodies. Accordingly in the various figures, 10 indicates a set of overhead tracks which support the traveling crane wheels 11 and constitute a trackway therefor. The wheels are journaled within a frame which may comprise longitudinal members 12, and transverse members 13 which I arrange in the form of a rectangle. The frame work may comprise channel beams which are held together in any convenient manner.

The hoisting mechanism shown comprises cables 14, 15, 16 and 17, which extend over sheaves 18, 19, 20 and 21 respectively. The sheaves are arranged adjacent the corners of a rectangle, whereby the vertical reaches of the cables may engage a removable truck body adjacent the four corners of a rectangle. To move the sheaves simultaneously, I have shown a screw and nut couple which is disposed adjacent the mid-portion of the frame. The nut as shown is attached to the cables and is arranged to be guided while moving longitudinally of the frame by guides 22 and 23. Such movement is effected whenever the screw or threaded shaft 24 is rotated.

In the preferred form the nut embodies two members 7 and 8 which may be loosely connected by dowel pins 9. The nut 7 is ordinarily of bronze and is arranged to carry the load stresses, while the nut 8 is preferably of steel and is normally idle but may carry the load as an emergency in the event of failure of the nut 7 due to wear on the threads. The nuts are normally out of contact, but clearance beyond the dowel pins in their sockets allows the bronze nut, should its thread be stripped, to come against the steel nut, which will thus support the load. This feature is covered in my divisional application No. 42,891 filed July 11, 1925.

To guide the cables, I have shown sheaves 26 and 27 which are disposed near one end of the frame for guiding the cable 14. Similar sheaves 28 and 29 are utilized for guiding the cable 15. Sheaves 30 and 31 preferably mounted on the same axis as the sheaves 26 and 27 are used for directing the cable 16, while sheaves 32 and 33 mounted on the same axis as the sheaves 28 and 29 are employed for guiding the cable 17.

To rotate the shaft 24, I have indict ted a hand chain wheel 3% which is mounted upon a shaft 35 and is operatively connected by gearing 36 to the shaft 24;. A thrust bear- -ing 37 may be disposed at one end of the shaft, whereby load stresses place the shaft under tension and thereby prevent deflection of the shaft while in use.

The sheaveslS and 19 are shiftable laterally upon curved trackways with reference to the frame for twisting the load with reference to the frame. The trackway for the sheave 18 is indicated as embodying an l.- shaped member 40 which extends between one of the beams 12 and a reinforcing beam A similar curved trackway for the sheave 19 is indicated at 11 as extending between one of the beams 12 and a reinforcing beam 6. In the preferred form, the sheaves 18 and 19 are rotatably mounted within carriages 4C2 1111(l4r3 respectively, and the carriages are operatively connected for simultaneous movement. As illustrated, each carriage has horizontally disposed wheels 44 which engage one arm of the curved trackway, and have vertically disposed wheels 41-5 for engaging the other arm of the traclnvay. Retaining members 46 and 47 may be positioned on the trackway for guiding the car riages during movement thereof.

The curvature of the trackways 4:0 and 11 permit the lateral shifting of the carriages with reference to the frame without raising the load. To effect such operation the curvature of the track is determined by the are of a circle which is described about a center which is the point of tangency of the horizontal sheave from which the cable runs to the shiftable vertical sheave. Thus the track 40 is an are about the point A, while the curvature of the track 41 is defined by the arc of a circle whichis described about the point B as a center. 'he points A and B are determined by the intersection of a line passing transversely of the frame thru the axes of the sheaves 26 and 29.

To shift the carriages simultaneously, I have shown a connecting rod 50 which is pivotally connected at 51 to the carriage 43 and at 52 to the carriage 4:2. Therod is illustrated as having a rack 53 which may be engaged by a pinion 54. To rotate the punch and therefore to shift the rack, I have indicated a hand chain wheel 55. which is mounted'upon a shaft 56. This shaft also carries the pinion. Accordingly, if the chain wheel is rotated 1n one direction, the carriages are simultaneously shifted in one direction, while if the chain wheel is rotated in the opposite direction, the directional movement of the carriages is reversed.

From the foregoing description, it w li be evident that I have provided asimple means for twisting a load with reference to the supporting frame without redu 4 one end of the load to be raised during the shifling operation. Moreover, I have obtained a mcchanisnr which is adapted for use with a hoisting apparatus which includes a screw and nut couple, wherefore the skewing device maybe mounted wit iin a crane having a very low over-all depth. This facilitates the installation within a building of low height without necessitating extensive changes in the building construction.

Having thus described my invention, I claim:

1. In combination, a frame, a sheave carried thereby, a lifting cable extending substantially the entire length of the frame and having a horizontal reach which at one end passes over the sheave and then depends, and means for shifting said sheave in an arcuate path about center substantially coincident with the other end of said horizontal reach, whereby a load nniy be twisted with reference to the frame.

2. In combination, a frame, load engaging elements depending therefrom, means for raising or lowerin said elements, and means if for shifting some of said elements in a curved path and with reference to the remaining elements for skewing a load with reference to the frame.

3. In combination, a frame, sheaves rot-atably mounted thereon, flexible load engaging elements extending over the sheaves, means for raising or lowerin said elements, and means for shifting some of said sheaves in a curved path with reference to the remaining elements for skewing a load with reference to the frame.

4. In combination, a frame, sheaves carried thereby, cables passing over the sheaves, and means for shifting some of said sheaves in an arcuate path with reference to the remaining sheaves, whereby a load depending from said cables may be twisted with reference to the frame.

5. In combination, a frame, sheaves carried thereby and arranged in pairs, cables passing over the sheaves, two of said sheaves being shiftable in a curved path with reference to the remaining sheaves, the path of travel of the two sheaves being similar, whereby a load depending from the cables may be skewed with reference to the frame.

6. In combination, a frame, a plurality of sheaves carried thereby, and cables extending in horizontal reaches for substantially the entire length of the frame and then passing over the sheaves, two of said sheaves being shiftable along arcuate paths with reference to the remaining sheaves, the ra 7. In combination, a ,frame four sheaves mounted thereon, caoles passing over the sheaves, curved trackways for two of said sheaves, means for raising or lowering said cables simultaneously, and means for moving two of said sheaves along the curved trackway simultaneously, said traclrways having such curvature that a load suspended from the cables may be twisted while the load remains level.

8. In combination, a rigid frame, four sheaves mounted thereon, four flexible raising members depending from said sheaves, and means for moving two of said sheaves in a curved path with relation to said frame and with relation to the remaining sheaves.

9. In a hoisting mechanism, the combina tion with a rigid frame, of four flexible rais ing elements mounted thereon, means for simultaneously raising or lowering said elements. four sheaves over which said elements extend, and means for shifting two of said sheaves as a unit along similarly curved paths relatively to the frame, and relatively to the other two sheaves.

10. In combination, a frame, two similarly curved trackways carried thereby, said trackways having spaced centers of curvature, a carriage on each trackway provided with a bearing wheel and having a sheave, cables extending horizontally to the respective sheaves and then depending from each carriage, a member operatively connecting the carriages and means for shifting the member transversely of the frame and of the horizontal reaches of the cables to move the carriages simultaneously in the same direction along the respective trackways.

1].. In combination, a frame, two arcuate traclrways carried thereby, said trackways having equal radii of curvature and different centers of curvature two wheeled-carriages movable along said trackways, respectively, a sheave mounted in each carriage, a flexible raising member passing over each sheave and having a load engaging member at its free end, means for moving the carriages simultaneously in the same direction with reference to the frame and along the respective trackways, whereby a load suspended from the cables may be shifted laterally.

12. In combination, a frame, two curved trackways carried thereby and having differentcenters of curvature, a wheeled carriage movable along each trackway, a sheave mounted in each carriage, a flexible raising member passing over each sheave, means for moving the carriages simultaneously with reference to the frame and along the respective traclnvays, whereby a load suspended from the cables may be shifted laterally while being maintained at the same height.

13. In combination a frame, two wheeledcarriages thereon. some of the wheels on the carriage being disposed on a vertical axis and others on a horizontal axis, sheaves mounted in the respective carriages, cables extending horizontally and then depending over the sheaves, a member connecting the carriages, a trackway on the frame engaging both the vertical and horizontal wheels, and means for shifting the member transversely of the horizontal reaches of the cable to move the carriages simultaneously along said trackway.

14L. The combination of a frame having transverse members with horizontal and vertical surfaces, a pair of carriages bearing against said horizontal and vertical sun faces, a pair of sheaves mounted in the re spective carriages, lifting cables extending horizontally over the sheaves and then depending, and means for shifting said carriages.

15. In a hoisting mechanism. the combination of a traveling frame. a transverse trackway thereon having substantially horizontal and substantially vertical portions, a pair of carriages having rollers bearing against said portions, a pair of sheaves mounted in said caniages respectively, cables extending horizontally over the sheaves and then depending to a load, means connecting the two carriages, and mechanism engaging said connecting member to shift the carriages in either direction, the vertical portion of said trackway being made areuate.

In .estimony whereof, I hereunto afiix my signature.

BENJAMIN F. FITCH.

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