US1068279A

US1068279A - Portable railway-crane.

Info

Publication number: US1068279A
Application number: US75325513A
Authority: US
Inventors: Wolfgang Schrader
Original assignee: Individual
Current assignee: Individual
Priority date: 1913-03-10
Filing date: 1913-03-10
Publication date: 1913-07-22
Anticipated expiration: 1930-07-22

Description

W. SGHRADER.

PORTABLE RAILWAY CRANE.

APPLICATION mum 2.10, 1913.

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1,068,279, Patented July 22, 1913.

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PORTABLE RAILWAY CRANE.

' APPLICATION FILED 11.10, 1913.

1,068,279. Patented July 22, 1913.

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W0 /f an fa/rrader m 525 J35 W UNITED STATES PATENT oFFIcE.

WOLFGANG SCHB-ADER, 0F BERLIN, GERMANY, ASSIGN'OB, TO ANTONIUS. LOUIS DE .BBUYNE, OF HILVEBSUM, NETHERLANDS.

PORTABLE RAILWAY-CRANE.

Specification of Letters I'atent.

Patented .iul I913.

Application filed lieu-oh 10, 1918. Serial No. 358,286.

have invented anew and useful Portable" Railway-Crane, specification.

My invention relates to a novel portable railway-crane with a movable boom pivot ally connected by means of three pairs of links with a frame, which is turnable on the carriage around a vertical main pivot;

The portlble crane is so constructed, that the boom can be moved forward for work and moved rearward for the trans rt of the crane.- When moved rearward th boom occupies 9. lowest approximately horizontal position, so that it falls within the compass of a profile or section generally allowed for the passage of any railway train and at the same time it fallswithi-n the limits of the outer length of the carriage, so that the portable crane can be coupled direct to any locomotive or inserted in any train without requiring any protecting car to be inserted between it and the locomotiveor the neighboring car or cars. By moving forward the boom can be raised into a more or less inclined position, so that the load can be lifted to a convenient height, while the radius of the boom is of course more or less increased. The portable crane may be so constructed, that its boom can be given two different radiuses and two different lifting heights, so that heavier and lighter weights can be equally well handled. A movable counterweight is provided for balancing the crane and is so connected with the rear end of the boom by means of ropes or the like, that by moving forward the boom the counterweight is at the same time moved to the rear outward on slightly ascending rails and that by moving the boom rearward the counterweight is at the same time by its own weight returned to its initial position. A single Windlass is provided in the frame for moving the boom forward and rearward andalso for raising and lowering the load. The three pairs of links for connecting the boomwith the frame are so disposed, that the rear end of the boom is pivotally connected with the rear pair of links and can slide with its two pivots in longitudinal slots of the middle pair of 1i '5. The front of which the following is a boom with the pair of links is at the upper end pivotally connected with the boom between its ends at a point neuer to the rear end. While the front pair of links serves for simply guiding the boom during its motion forward and rearward, the rear pair of links serves for turning the boom during its forward motion into its raised inclined position and duringthe rearward into its lowest approximately horizontal position.

The middle pair of "links makes with the. rear psir, when looked atfrom a side, a variable triangle, the vertex of which lies-in the rear end of the boom. A segment is provided on the carriage and the lower-midsof the two 7 links in the near pair are madetdproject downward from the pivots, so that they can compass the sit on thecan'ia lowest horizontal Po ition :04 m and thusloek it for prevemting'th'e mm from turning on the carris For the upper" raised position of' the li oom the said. profooting lower ends of the rear links are out of the reach of the segment, so that the lend our be freely turned around the vertical axis of the main pivot. Other features of the invention. wikl be hereinafter set forth and pointed. out in the claims.

I willnow to deseribe my invention with re erence to the accompanying drawings, in which- Figure 1 diagrammatically shows the upper part of the novel portable railwaymmne,

the boom occupying its lowest horizontzi position for the minimum radius, oniy so many parts shown as is sufiicient for the understanding of the invention. Fig. 2 is a similar diagram to show the boom in its middle less inclined position for an intermediate radius. Fig. 3 is a similar diagramto'show the boom in its extreme raised inclined position 'for the maximumradius, Fig. 4 is :m elevation of the complete portable railway crane, the boom: 0ccuipying its extreme raised position for the maximum radius in correspondence with Fig. 3 Fig. 5 is a: vertical longitudinal section through the some, the carriage being. shown in elevation. F' 6 is a front end View of the same, Fig. is an upper view of the some, and Fig. 8- is an 11' r view of the carriage alone, the VBliilCBsl mainpivot being shown in section.

for the .is nearly horizontal and the Similar characters of reference refer to similar parts throughout the several views.

On a suitable carriage 1 are disposed a vertical main pivot 2 (Figs. 5 and 8), a concentric circular rail 3 and a concentric segmental projection 4 serving as a stop. A suitable number of carrying-rollers 5 (Fig. 5) adapted to roll on the circular rail 3 are disposed in a suitable carrying frame 6, which is mounted to turn around the main pivot 2. I do not further describe the carriage 1 nor the carrying frame 6, as their construction is immaterial to my invention and may be varied in any known manner.

The carrying frame 6 is rigidly connected with a main frame 7 having about the shape of a lying L (Figs. 4 and 5) and shown as made from wrought iron plates and angleirons. In the horizontal part of the main frame 7 three parallel

horizontal rods

8, 9', 10 are fastened, the outer ends of which serve as

pivots

8, 9, 10. On the front pivots 8, 8 a pair of

parallel links

11, 11 is mounted to rock, which at the upper end is pivotally connected with a boom 12 of any known construction by means of its

pivots

13, 13 that are shown as formed b the outer ends of a cross rod 14 (Fig. 5) astened in the boom. The rear end of the boom 12 is provided with a cross shaft 15, the outer ends of which serve as

pivots

15, 15 that are con- 1 nected with the

rear pivots

10, 10 below by means of a rear pair of

parallel links

16, 16. On the middle pivots 9, 9 a third pair of

parallel links

17, 17 is mounted to rock, which links are for the upper part provided with longitudinal slots 18, in which the two

rear pivots

15, 15 of the boom 12 are guided, so that in this manner the upper ends of the

rear links

16, 16 are also pivotally connected with the upper parts of the middle links 17 17. It is evident, that in the elevation the middle links 17 17 make with the

rear links

16, 16 and the base a triangle, which. in shape varies during the motion of the boom 12 in either direction. For the extreme rear position of the boom 12 shown at Fig. 1 it ivots 15, 15 bear against the upper ends 0 the slots 18. For the extreme front position shown" at Fig. 3 the boom 12 is most inclined and the

pivots

15, 15 bear against the lower ends of the slots 18. Obviously the

frontlinks

11, 11 support the boom 12 and guide it during the forward and rearward motion, while the

rear links

16, 16 pull the rear end of the boom downward whereby the front end of the same is raised.

Thet-wo

middle links

17, 17 are about in their middle connected together by means of a rod 19 (Fig. 5), on the outer ends of which two

parallel locks

20, 20 are fastened. Each lock 20 has two superposed

hooks

21, 22 and should be pressed rearward in any known manner. so as to bear against the upper rear pivots 15. For example the two

locks

20, 20 are shown to have each a lower inclined arm 23 with a handle 24. The

lower arms

23, 23 are widened so as to serve as weights which press the

locks

20, 20 rearward. The rear upper pivots 15, 15 are to engage either 'in the upper hooks 21 (Fig. 2) or in the lower hooks 22 (Figs. 3 and 4).

Within the vertical part of the main frame 7 a suitable Windlass 25 (Fig. 5) is disposed, which is shown as comprising a drum 26, a double purchase lifting gear, two winch-handles 27, a strap brake 28 and a lever 29 for same. A suitable block 30 having a long shaft 31 is suspended from the front end of the boom 12 by means of

ropes

32, 32 passing on the one hand over a balancing sheave 33 and on the other hand over two sheaves 34 at the front end of the boom 12 and two

sheaves

35, 35 loose on the shaft 15 to-the drum 26. Two

parallel stop plates

36, 36 having each two

notches

37, 38 are rigidly connected with the upper end of the b00111 12 and serve for checking the up ward motion of the block 30, the outer ends of the shaft 31 being capable of engaging either in the front notches 37 (Figs. 1 and 2) or in the rear notches 38 (Fig. 3).

The upper side edges of the horizontal part of the main frame 7 are slightly inclined so as to ascend outward and serve as rails for the

wheels

39, 39 of a movable counterweight 40. Loose on the shaft 15 in the rear end of the boom 12 are two

parallel links

41, 41, which are connected with the inner end of the counterweight 40 by means of two

ropes

42, 42 passing over two guiding

pulleys

43, 43 loose on a shaft 44 that is fastened in the rear end of the frame 7. The counterweight 40 is at the rear provided with a hook 45, in which the rod 19 in the middle pair of

links

17, 17 can engage (Fig. 1) for preventing the counterweight 40 from motion during the transport of the crane. Preferably the vertical part of the frame 7 is made so high (Fig. 1) as to support the front part of the boom 12 in its lowest and extreme rear position. Two opposite stops 46, 46 (Fi 6) are fastened on the upper surface of t is front frame part for preventing the boom 12 from lateral motion during the transport of the crane. The said vertical part of the frame 7 is preferabl made horizontally so long (Fig. 4) as to ear against the inner sides of the two

front links

11, 11 for preventing the boom 12 from shaking during its revolution around the main pivot 2. The

rear links

16, 16 are so much lengthened downward from the

pivots

10, 10, as to be capable of bearing against the two end faces of the segmental stop 4 (Fig. 8) for the lowest and extreme rear position of the boom (Fig. 1) ,so as to prevent the crane from turning on the carriage 1 during the transport. A suitable a the boom 12 forward while turning its rear platform 46; may be provided on the main frame 7 for supporting the workmen.

The portable railway-crane described opl erates as follows: As already mentioned 1 above, the boom 12 normally occupies its lowest and extreme rear position shown at f Fig. 1, the outer ends of the shaft 31 of the block 30 engaging in the front notches 37 of l the stop plates 36, so that the transportable l crane can be coupled to any locomotive or train and therewith moved to the respective place for work without encountering any: obstacle since its boom is within the compass of a profile or section generally allowed for i the passage of any train. When it is de- 1 sired to raise and move forward the boom 12 into the middle position for the intermediate radius indicated at Fig. 2 and to handle heavier loads, first the two

winchhandles

27, 27 are turned in the hoisting direction. As the outer ends of the shaft 31 of the block 30 engage in the front notches 37 of the

stop plates

36, 36 and are thus pre-- vented from upward motion relatively to the been: 12 and only the two ropes 32, between the two

rear sheaves

35, 35 and the drum 2? (Fig. 5) are capable of being shortened. the consequence of the revolution of the two winch-

handles

27, 27 will be to pull end downward and its front end upward. Then the upper hooks 21 of the two locks 29. 21" will soon strike the rear pivots 15, 15 of the boom and ride over them, until the

pivots

15, 15 slide beneath the lower ends of the upper hooks 21. which then snap behind them, the two locks 20. 2 turning downward. Therenpon the two winch-handles 27. 27 are turned! in the opposite direction or may he reieased while the brake lever 29 is oprrated for allowing the

pivots

15, 15 to fully engage in the upper hooks 21 (Fig. 2). Vv'hen the brake 28 is further released, the boom 12 will not. any more alter its position out the block 30 will simply lower, as it is no longer checked by the two

stop plates

36, 36. The counterweight 10 has meanwhile been liberated by the cross shaft 19 of the middle pair of links 17. 17 moving out of its hook 15 and then drawn out ward by means of the two links -11, 41 and the two ropes -12, 12 and will now occupy its middle position shown at Fig. At the same time the lower ends of the

rear links

16, 16 will have moved out of the reach of the segmental stop 1, so that the crane can now turn on the carriage 1 around the main pivot 2 in either direction. The load to be lifted is then attached to the double hook of the olock 30, whereupon the two winch handles 27, 27 are turned in the hoisting direction. so that the block 30 will rise and lift the load to the desired height. whereupon the boom 12 with all the movable parts connected therewith can be turned around the main pivot 2 in the desired direction. When it is desired to further raise the cathead and to move the boom 12 into the extreme front position for the maximum radius shown at Figs. 3 to 5, then the two winch-

handles

27, 27 are turned in the hoisting direction. until the outer ends of the shaft 31 of the block 30 engage in the front notches 37 of the two

stop plates

36, 36, and the rear end of the boom 12 is so much pulled downward, that the

pivots

15, 15 move out of the upper hooks 21 and slide first on the rear edges of the

locks

20, 20, then on the backs of the two lower hooks 22, whereupon the latter snap behind them. At this moment the two winchhandles are either turned in the other direction or released while the brake lever 22) is operated for permitting the

pivots

15, 15 to fully engage in the lower hooks 22, Whereuponthe outer ends of the block shaft 31 move out of the front notches 37 cf the two

stop plates

36, 36 and the crane will be ready for work. At this moment the wheeled counterweight -10 will occupy its extreme outer position shown.

In order to return all the parts of the crane into the initial position, first the two winchhandles 27. 27 are turned in the hoisting direction. until the outer ends of the block shaft 31 engage in the rear notches 38 of the two stop plates 36, 36 (which notches are now about in the vertical plane of the shaft 31, as can be seen from Figs. 3 to 5) ahd the two pivots 15. 15 move downward in the slots 18 of the

rear links

17, 17 out of the reach of the lower hooks 22, whereupon the

handles

24, 21 are moved to the rear for turning the two stops 20, 20 to the front (that is to the left in Figs. 3 to 5) and the two

winchhandles

27, 27 are turned in the opposite direction or released while using the brake 28, as the case may be. It is to be borne in mind, that the over-weight of the boom 12 (its center of gravity being on the front side of the pi ots 13, 13) tends to press the two

rear pivots

15, 15 upward in the slots 18 of the two

middle links

17, 17. When the two pivots 15. 15 have moved upward out of the reach of the lower hooks 22, the two

handles

24, 24 are released. so that the two

pivots

15, 15 now slide on the rear edges of the two stops 20, 20 and engage in the two upper hooks 21. At this moment the two outer ends of the block shaft 31 will move out of the rear notches 38 of the two

stop plates

36, 36 into the vertical plane of the front notches 37 (Fig. 2). Then the two winch-

handles

27, 27 are again turned in the hoisting direction, so that the outer ends of the block shaft 31 engage in the front notches 37 of the two stop plates 36, 3t) and the two rear upper pivots 15, 15 move downward in the slots 18 of the

middle links

17, 17 out of reach of the upper books 21, whereupon the two

handles

24, 24 are moved to the rear for turning the two

locks

20, 20 forward and the two winch-

handles

27, 27 are turned in the opposite direction or released while using the brake 28, so that the rear pivots 15, 15 move upward in the slots 18 of the

links

17, 17 and the boom 12 sinks into the lowest and extreme rear position shown at Fig. 1.

The portable railwaycrane can be varied in. many respects without departing from the spirit of my invention.

I claim: 7

1. In a portable crane, a carriage, a frame on said carriage havin three parallel pairs of opposite pivots, a 00m having at the rear end a rear pair of opposite pivots and intermediate the ends a middle pair of opposite pivots, a rear pair of links rocking on the rear pair of pivots of said frame and pivotally connected with the rear pair 'of pivots of said boom, a front pair of links rocking on the front pair of pivots of said, frame and pivotally connected with the middle pair of pivots of said boom a middle pair of links rocking on the middle pair of pivots of said frame and being for the upper part adapted to longitudinally guide the rear pivots of said boom, and means, for varying the distance between the rear pair of pivots of said boom and the front pair of pivots of said frame, whereby said boom is moved rearward into a lowest position for the minimum radius or moved forward into a higher or highest position for an intermediate or the maximum radius.

2. In a portable crane, a carriage, a frame on said carriage having three parallel pairs of opposite plvots, a boom having at the front end a pair of notched stop plates, at

/ the rear end a rear pair of opposite pivots and intermediate the ends a middle pair of opposite pivots, a rear pair of links rocking on the rear pair of pivots of said frame and pivotally connected with the rear pair of pivots of said boom, a front pair of links rocking on the front pair of pivots of said frame and pivotally connected with the middle pair of pivots of said boom, a middle pair of links rocking on the middle pair of pivots of said frame and being for the upper part adapted to longitudinally guide the rear pivots of said boom, a block comprising sheaves and .a shaft adapted to engage in the notches of said stop plates and to be thereby checked in the upward motion, sheaves at both ends of said boom, a drum in said frame, drawing means passing from the front end of said boom around the sheaves of said block and over the sheaves at both ends of said boom to the front to said drum, means for longitudinally adjusting the rear pivots of said boom on said middle pair of links, and means for turning said drum in either direction so as to raise and lower the load when said block is free of said stop plates or to move said boom rearward into a lowest position for the minimum radius or forward into a higher or highest position for an intermediate or maximum radius, when the shaft of said block engages in the notches of said stopv plates.

3. In'a portable crane, a carriage, a frame on said carriage having three parallel pairs of opposite pivots, a boom having at the rear end a rear pair of opposite pivots and intermediate the ends a middle pair of opposite pivots, a rear air of links rocking on the rear pair of pivots of said frame and pivotally connected with the rear pair of pivots of said boom, a front pair of links rocking on the front pair of pivots of said frame and pivotally connected with the middle air of pivots of said boom, a middle pair of links rocking on the middle pair of pivots of said frame and having for the upper part longitudinal slots in which the rear pivots of .said boom. are aided, and means for varying the distance tween the rear pair of pivots of said boom and the front pair of pivots of said frame, whereby said boom is moved rearward into a lowest position for the minimum radius or moved forward into a higher or highest position for an intermediate .or the maximum radius.

'4. In a portable crane, a carriage, a frame on said carriage having three parallel pairs ofopposite pivots, a boom having at the front end a pair of notched stop plates, at the rear end a rear pair of opposite pivots and intermediate the ends a middle pair of opposite pivots, a rear pair of links rocking on the rear pair of pivots of said frame and pivotally connected with the rear pair of pivots of said boom, a front pair of links rocking on the front pair of pivots of said frame and pivotally connected with the middle pair of pivots of said boom, a middle pair of links rockingon the middle pair of pivots of said frame and having for the upper part longitudinal slots in which the rear pivots of said boom are guided, a block comprising sheaves and a shaft adapted to engage in the notches of said stop plates and to be thereby checked in the upward motion, sheaves at both ends of said boom, a driun in said frame, drawing means passing from the front end of said boom around the sheaves of said block and over the sheaves at both ends of said boom to the front to said drum, means for adjusting the rear pivots of said boom in the longitudinal slots of said middle pair of links, and means for turning said drum in either direction so as to raise and lower the load when said block is free of said stop plates or to move said boom rearward into a lowest position for the minimum radius or forward into a higher or highest position for an intermediate or maximum radius, when the shaft of said block engages in the notches of said stop plates.

5. In a portable crane, a carriage, a frame turnable on said carriage around a vertical axis and having three parallel pairs of opposite ivots and two parallel inclined rails ascendlng outward, a boom having at the rear end a rear pair of opposite pivots and intermediate the ends a middle pair of opposite pivots, a rear pair of links rocking on the rear pair of pivots of said frame and pivotally connected with the rear pair of pivots of said boom, a front pair of links rocking on the front pair of pivots of said frame and ivotally connected with the middle pair 0 pivots of said boom, a middle pair of links rocking on the middle pair of pivots of said frame and being for the upper part adapted to longitudinally guide the rear pivots of said boom, means for varying the distance between the rear pair of pivots of said boom and the front pair of pivots of said frame so as to move said boom rearward into a lowest posit-ion for the minimum radius or forward into a higher or highest position for an intermediate or the maximum radius, a wheeled counterweight rolling on the inclined rails of said frame, guiding pulleys at the rear end of said frame, and drawing means connecting the rear end of said boom with said counterweight and passing over said guiding pulleys.

6. In a portable crane, a carriage, a frame turnable on said carriage around a vertical axis and having three parallel pairs of opposite pivots and two parallel inclined rails ascending outward, a boom having at the front end a pair of notched stop plates, at the rear end a rear pair of opposite pivots and intermediate the ends a middle pair of opposite pivots, a rear pair of links rocking on the rear pair of pivots of said frame and pivotally connected with the rear pair of pivots of said boom, a front pair of links rocking on the front pair of pivots of said frame and pivotally connected with the middle pair of pivots of said boom, a middle pair of links rockingon the middle pair of pivots of said frame and being for the upper part adapted to longitudinally guide the rear pivots of said boom, a block comprising sheaves and a shaft adapted to engage in the notches of said stop plates and to be thereby checked in the upward motion, sheaves at both ends of said boom, a drum in said frame, drawing means passing from the front end of said boom around the sheaves of said block and over the sheaves at both ends of said boom to the front to said drum, means for longitudinally adjusting the rear pivots of said boom on said middle pair of links, means for turning said drum in either direction so as to raise and lower the load when said block is free of said stop plates or to move said boom rearward into a lowest osition for the minimum radius or forward into a higher or highest position for an intermediate or maximum radius, when the shaft of said block engages in the notches of said stop plates, a wheeled counterweight rolling on the inclined rails of said frame, guiding pulleys at the rear end of said rame, and drawing means connecting the rear end of said boom with said counterweight and passing over said guiding pulleys.

7 In a portable crane, a carriage, a frame posite pivots,

on said carriage havin three parallel pairs of opposite pivots, a 00m having at the rear end a rear pair of opposite pivots and intermediate the ends a mlddle pair of opa rear pair of links rocking on the rear pair of pivots of said frame and pivot-ally connected with the rear pair of -pivots of said boom, a front pair of links rocking on the front pair of pivots of said frame and ivotally connected with the middle pair 0 pivots of said boom, a middle pair of links rocking on the middle pair of pivots of said frame and being for the upper part adapted to longitudinally guide the rear pivots of said boom, and means for varying the distance between the rear pair of pivots of said boom and the front pair of pivots of said frame, whereby said boom is moved rearward into a lowest position for the minimum radius or moved forward into a higher or highest position for an intermediate or the maximum radius, said frame bein adapted to support the front art of said boom in its lowest position an to prevent it from lateral motion.

8. In a portable crane, a carriage, a frame turnable on said carriage around a vertical axis and having three parallel pairs of opposite pivots, a boom having at the rear end a rear pair of opposite pivots and intermediate t e ends a middle pair of opposite pivots, a rear pair of links rocking on the rear pair of pivots of said frame and pivotally connected with the rear pair of pivots of said boom, a front pair of links rocking on the front pair of pivots of said frame and pivotally connected with the middle pair of pivots of said bdbm, a middle pair of links rocking on the middle air of pivots of said frame and being for t e upper part adapted to longitudinally guide the rear pivots of said boom, and means for varying the distance between the rear pair of pivots of said boom and the front pair of pivots of said frame, whereby said boom is moved rearward into a lowest position for the minimum radius or moved forward into a higher or highest position for an intermediate or the maximum radius, said frame being adapted to support the front part of said boom in its lowest position and to bear against the inner sides of said two front links for preventin said boom in its highest position from s aking during the rotation of the carriage around the vertical axis.

9. In a portable crane, a carriage, a frame on said carriage having three parallel pairs of opposite pivots and two parallel inclined rails ascending outward, a boom having at the rear end a rear pair of opposite pivots and intermediate the ends a middle pair of opposite pivots, a rear pair of links rocking on the rear pair of pivots of said frame and pivotally connected with the rear air of pivots of said boom, a front pair of links rocking on the front pair of pivots of said frame and pivotally connected with the middle pair of pivots of said boom, a middle pair of links rocking on the middle pair of pivots of said frame and being for the upper part adapted to longitudinally guide the rear pivots of said boom, means for varying the distance between the rear air of pivots of said boom and the front pair of pivots of said frame, whereby said boom is moved rearward into a lowest position for the minimum radius or moved forward into a higher or highest position for an intermediate or the maximum radius, a wheeled counterweight rolling on the inclined rails of said frame and provided at the outer end with a hook, guiding pulleys at the rear end of said frame, drawing means connecting the rear end of said boom with said counterweight and passin over said guidin rod between said mi dle links ada ted to engage in the hook of said counterweight for the lowest position of said boom so as to prevent said counterweight from motion during the transport of the crane.

pulleys, and a cross 10. In a portable crane, a carriage, a frame turnable on said carriage around a vertical axis and havin three parallel pairs of opposite pivots, a 00m having at the rear end a rear pair of opposite pivots and intermediate the ends a middle pair of op-. posite pivots, a rear pair of links rocking on the rear pair of pivots of said frame and pivotal-1y connected with the rear pair of pivots of said boom, a front pair of links rocking on the front pair of piyots of said frame and pivotally connected with the middle pair of pivots of'said boom, a middle pair of links rocking on the middle air of pivots of said frame and being for t e upper part adapted to longitudinall guide the rear pivots of said boom, means or varying the distance between the rear pair of pivots of said boom and the front pair of pivots of said frame, whereby said boom is moved rearward into a lowest position for the minimum radius or moved forward into a higher or highest position for an intermediate or the maximum radius, and a stop on said carriage, said rear links being so much lengthened downward beyond the rear pivots of said frame as to compass said stop for the lowest position of said boom so as to prevent the crane from turning on said Carriage during the transport, While by moving said boom' forward the lower lengthened ends of said rear links are moved out of the reach of said stop for permitting the crane to turn.

WOLFGANG SCHRADER.

Witnesses HENRY HASPER, WoLnEMAR HAUP'I.