US1838939A - Lifting mechanism for traversing hoists - Google Patents

Description

Dec. 29, 1931. G A. GRAB LIFT'TNG MECHANISM FOR TRAVERSING HOISTS 7 3 Sheets-Slieet Original Filed July 23. 192'? //\/4/5/\/ TUK 7 7-7-UF /VE Dec. 29, 1931. G. A. GRAB 1,838,939-

LIFTIGG MECHANISM FOR TRAVERSING HOISTS Original Filed July 23. 1927 3 Sheets-Sheet 2 m-WW 4 7- 77:7 KNEW Dec. 29, 1931. 54 A. GRAB LIFTING MECHANISM FOR TRAVERSING HOISTS 192'? 3 Sheets-Sheet 3 Original Filed July 23,

Patented Dec. 29, 1931 UNITED STATES PATENTOFFIICAE GUSTAV A. GRAB, OF PORTLAND, OREGON, ASS IGNOR, BY MESNE ASSIGNMENTS, 'I.0

WILLAMETTE-ERSTED COMPANY, OF PORTLAND, OREGON mrrme macnmisir roa TRAVERSING- nors'rs Substitute for application Serial No. 207,873, fllcd Iuly 23, 1927. This application filed Kay 26, 1930.

' Serial No. 455,927. I

This application is substitute for application Serial Number 207,873 filed July 23, 1927 and the invention relates enerally to traversing hoists, and particular y to a special form of lifting mechanism whereby loads may be picked up or lowered.

The first object of this invention is to provide a special form of lifting mechanism for traversing hoists which can be operated from the hoist engine independently of any other duties which such engine is performing.

The second object is to provide a dry transmission for the lifting mechanism to eliminate the undesirable scattering of oil over the lumber or other material being handled.

The third object is to provide an exceedingly quiet and smoothly operating lifting a mechanism which will require only a minimum application of hand power from the operator to control the lift which is locked in any osition it is moved by the operator.

The ourth object is to so construct the lift that the clearance between its upward and downward driving positions is'exceedingly snall, thereby making large lever ratios possi le.

The fifth object is to so construct the drive that there will be no danger from wearing flat spots on the friction element.

The sixth object is to provide a plurality of automatic stops for the lifting mechanism which will disengage same in either its upward or downward limit of travel, without v load, and in its upward limit of travel, with load.

The seventh object is'to combine the load stops to the load binding mechanism.

These, and other objects, will become more apparent from the specification following as illustrated in the accompanying drawings, in which:

Figure 1 is a side elevation of a traversing hoist. Figure 2 is a diagrammatic .view showing the friction gearing in a load lifting position. Figure 3 is "similar to Figure 2 but showing the gears in a lowering position. Figure 4 is similar to Figures 2 and3 showing the parts in a neutral position. Figure 5 is a perspective viewa'of the hoist frame and the parts related to this invention. Figure 6 is an enlarged side elevation of the combined load stop and load binding mechanism. Figure 7 is a transverse section taken along the line 77 in Figure 5 Figure 8 is a broken section taken along the line 8-8 in Figure 7. Figure 9 is a horizontal section taken along the line 9-9 in Figure 7. A

Similar numbers of reference refer to similar parts throughout the several views.

Referring in detail to the drawings, there is illustrated the frame of a traversing hoist including the corner posts 11 which carry the spindles 12 of the wheels 13, and also the cross ties 1 f which join the posts 11 laterally, while the cross ties 15, 16 and 17 .join the members 11 longitudinally. There is also in-' dicated the propeller shaft 18 of a motor 18A. The propeller shaft 18 is joined by a "flexible coupling 19 to the extension shaft 20, which passes through the housing 21 which, in turn, extends laterally across the hoist and is secured to the members 15 by means of the bolts 22. It will be understood that the shaft 18 is preferably at the forward end of the motor 18-A from whose rearward end the hoist may be propelled along the ground in any desired manner.

On the shaft 20 is keyed the flanged cent'er 23 of the friction wheel 24, which is clamped to the member'23 by the bolts 25 and the ring 26. The under side of the member 21 is open and is provided with the downwardly projecting arms 27, between which is hinged the rockable frame 28 which is mounted on the shaft 29 whose ends are supported by the eccentric bushings 30 in the arms 27. The shaft 29 is pinned to both of the eccentric bushings 30 can be held in any desired position.

In the rockable frame 28 are mounted the shafts 32 and 33 on which are keyed the gears 34 and 35 which mesh at all times. On the shafts 32 and 33 are also secured the friction wheels 36 and 37 which, mainly for thepurpose of assisting in better showing their acttion, are shown of unequal size.

It will be noted in Figures 2, 3, 4 and 7 that either of the wheels 36 or 37 can be brought into engagement with the wheel 24, or both may be held out of engagement therewith. In order to rock the frame 28 and produce the desired kind and degree of engagement between the various friction wheels'there is provided a rotatable shaft 38 having on opposite ends thereof the oppositely threaded portions 39 which are carried by the wrist pins 40 in the arm 41 and the wrist pin 42 in the bracket 43. The shaft 38 is rotated by means of a lever 44 which is securely mounted thereon and to whose endis attached a connecting rod 45 whose opposite end is attached to a lever 46 on the rock shaft 47 which is operated by a hand lever 48 whose quadrant 49 is provided with a single notch 50 which corresponds with the neutral position in which the friction wheels are held out of engagement.

It canbe seen that by making-the pitch of the threads 39 on the shaft 38 suitable for the purpose that the friction applying mechanism is self locking and that a great deal of pressure can be applied to the friction surfaces without the exertion of much manual efl'ort.

On account of this construction it is necessary that the total of the clearances between the wheel 24 and the wheels 36 and 37 shall be kept to the minimum, which is rendered easily possible by the eccentric mounting for the shaft 29.

On the shaft 33 are mounted the sprockets 51 whose chains 52 pass around the sprockets 53 on the longitudinal shafts 54, which are mounted in the brackets 55 on the ties 16. The shafts ,54 are provided with threaded ends 56 on which are placed the traveling nuts 57. From each nut 57 extend the side links 58 which are attached to the bell crank lever 59 on the bracket 60. The bell crank lever 59, in turn, operates the lifting rod 61 which operates the load lifting mechanism- 62, which is fully described in my Patent 1,734,330, issued November 5, 1929.

In order to prevent the nuts 57 from turn mg there is provided for each of same a horizontal guide 63. Astarting crank 64 is also provided on the forward tie 14 for the purpose of applying rotary motion tothe shaft 20 as when starting. The usual spring 65,

as is common witlieranks of this nature, is

also employed.

Alongside of one shaft 54 is mounted a slidable rod 66 whose forward end is supported in the arm 57A which projects from a. trunnion of a nut 57. The rod 66 carries in front of the arm 57A a pair of nuts 68 which engage the arm 57A when the load l1 fting mechanism is in its lowermost position. The rearward end of the rod 66 passes through the arm 67, which is keyed to the shaft 68A which, in turn, journals in the bearing 69. The rod 66 is provided with a threaded end 70 which extends into the slotted coupling 71 to which motion can be supplied by the lever 72 which is pivotally mounted on the pin 73. The lever 72 is, in turn, adapted to be rocked by the connecting rod 74 .which is attached to the lever 75 on the shaft 47.

On the threaded portion 70 of the rod 66 are placed the nuts 76 and on the opposite side of the arm 67 is secured the adjustable stop 77.

On the shaft 68--A are mounted the downturned arms 78 on whose lower ends are secured the channel bar 79 which is urged downwardly by the springs 80 whose upper ends bear against the ties 15.

The operation of the device is as follows: When it is desired to pick up a load of lumber the carrier is driven straddle the pile, as is a matter of common knowledge, and the particular load engaging mechanism employed is operated so that the load will be engaged. It is assumed that the engine-is running and the lever 48 is now moved away from its neutral position so as to rock the shaft 47 in a manner that the frame 28 will swing into the position shown in Figure 7,

wherein the wheel 37 engages the wheel 24. The wheel 36 is now being idly driven and is not transmitting any power whatsoever; whereas the wheel 37 is rotating the shafts 54 in a manner to lift the load. I

When the load is raised sufiiciently high the operator merely moves his lever 48 to the neutral position where it is held by the notch 50. The notch 50 has, in reality, a double functionfirst the preventing of the lever 48 from being carried away from its neutral position by gravity and vibration and second that of insuring that the wheels 36 and 37 willbe held completely out of engagement when in the neutral position.

If, for any reason, the operator should fail to move the lever 48 manually when a load is moved to the uppermost height, namely when it comes in contact with the bar 7 9, then the first thing which transpires is that the springs 80 are put in compression, thereby causing the bar 79 to serve as a load binder.

However, as the bar 79 moves upwardly it 1 rocks the shaft 68A and causes the arm 67 to engage the nuts 76 and ultimately, through the lever 72 and the parts 74 and 75, causes the hand lever 48 to move to its neutral position.

If it is desired to lower a load the hand lever 48 is moved in the opposite direction from that above described, causing the wheel 36 to be brought into engagement with the wheel 24, in which case the wheel 36 acts as an idler, and since this is a lowering operation it has, in reality, very little, if any, driving action to perform. i

In case the operator fails to disengage his friction wheels manually on the downward travelthen the arm 5 7A will engage the nuts 68 and automatically stop the mechanism. The same is true of the upward unloaded position of travel, in which case the arm 67 engages the stop 77 and automatically shifts the lever 48 to the neutral position.

Again, owing to the fact that cylindrical friction units are employed instead of conical it will be almost impossible to wear fiat spots thereon, since the friction element which is most easily worn, is the rotating member, whereas the others aremetal.

By this constructionit is possible to secure a very smooth operation for the hoist, which greatly adds to its life, as well as decreases its maintenance cost.

Where other load binders are required in front of or behind the one illustrated these can consist of spring urged bars similar to the bar 79 against which the load can be raised and thereby securely bound.

I am aware that many forms of traversing hoists have been constructed in the past; it is therefore not my intention to cover such devices broadly, but I do intend to cover all such forms and modifications thereof as fall fairly within the appended claims.

I claim:

1. Ina traversing hoist, the combination of a wheeled frame; a motor mounted on said frame having a load lifting power take-off at one end of its crank shaft; with a load lifting transmission taking its power directly from said engine; a sprocket operated load lifting shaft member at each side of said frame; a reversible shaft frietion'ally driven from said load lifting power takeoff; sprockets on said reversible shaft; and chains connecting said sprockets with said load lifting sprockets.

2. In a traversing hoist, the combination of a wheeled frame having a load lifting mechanism mounted thereon and having a power unit mounted on said frame, said power unit having its load lifting takeoff at the forward end thereof; driving connections between said propelling takeoff and said wheeled frame, a friction wheel on said load lifting takeoff; a rockable frame mounted adjacent to said friction wheel; a pair of friction wheels mounted on said rockable frame having gears thereon for driving same in opposite directions but having their friction faces separated from each other; means for moving said rockable frame so that either or neither of said geared friction wheels engage the friction wheel on the load lifting takeoff: and driving connections between one of said geared friction wheels and said load lifting mechanism.

3. In a traversing hoist, the combination ofa vehicle frame including load-lifting members with an operating motor mounted on said hoist and having a load lifting transmission mounted in front of'the cranking end ofthe motor, said transmission comprising a transmission frame; an extension for the crank shaft of the motor journaling in said frame; a friction wheel on said extension shaft; a rockable frame hinged to said transmission frame; a pair of meshing gears mounted on said rocker frame, one of said gears delivering power to the load lifting members of the hoist, both of said gears having friction wheels attached thereto but not contacting with each other; and screw means for operating said rocker frame in a manner that either or neither of said gear friction wheels will engage the friction wheel on said extension shaft.

4. A traversing hoist including a hoist propelling shaft with an engine for driving same and having load lifting mechanisms mounted thereon and a load lifting transmission operable independently of the hoist propelling transmission, said load lifting transmission consisting of a friction wheel driven directly by the engine; a pair of friction wheels rockably mounted alongside of said first mentioned wheel; means for rocking said friction wheels in a manner that either or neither of same are brought into engagement with said engine driven friction wheel; a pair of meshing gears attached to said rockable friction wheels for driving same in opposite directions; and chain and sprocket members between one' of said rockable gears and the lifting mechanism of the hoist.

GUSTAV A. GRAB.

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