US1836218A - Hoisting device - Google Patents

Description

Dc. 15, 1931. c, WRI H 1,836,218

HOISTING DEVICE Filed May 21, 1929 2 Sheets-Sheet l I V NT R.

A TTORNEYS.

Dec. 15 1931. c. G. WRIGHT 1,836,218

HOISTING DEVICE Filed May 21, 1929 2 Sheets-Sheet 2 if INVENTOR.

ATTORNEYS.

Patented Dec. 15, 1931 UNITED STATES YP TENToFFIc f 'wwwwl CHARLES G. WHICH-I101? RIGHMQN'ID HILL, NE YORK, AssIeNoR, BY MESNE Assriv- MENTS, TO BUcYRUs-ER-IE COMPANY, OF soU'rHMILwAU rEE, wrsoonsm, ALCOB- roRATI'on OF DELAWARE I Hors'rrnG nnvrc n Application filed May 21, 1929. Serial Nb. 364,737.

This invention relates to an improvement in hoisting devices, the invention being directed particularly to an automatic take up and: latching mechanism for the load line in that type of hoisting apparatus comprising a boom supported or carried by a rotatable mast.

' In hoisting apparatus of this type a hoisting cable is employed for raising and lowering the boom, and a holding line for supporting the load, the former passing about a sheave carried by the boom, the latter'pa'ssing over-a sheave carried by the boom, one

end of this holding line being anchored to the mast and the other end being operatively-connected to a latch mechanism carried by the mast. p

Still more specifically, the apparatus, of this invention comprises a drum to which the inboard end of the holding line is attached, this drum being spring-actuatedin a direction to take up the slack in the holding line asthe boom of the apparatus visraised, the drum rotating in the opposite direction on lowering of the boom. The drum is held, in position by pawl and ratchet mechanism 'hich may be released manually to permit the drum to rotate and the holding line to'be unwound therefrom. As a safety feature have provided two sets of pawls for the drum so arranged that one pawl will take the load should the other. be inoperative for any reasont I have also provided I, an improved and novel construction for attaching the holding cable to the drum and for; attaching the drum spring to the shaft on which the drum is mounted for rotation andiby which spring the drum is caused to rotate in a direction to windor reel up the holdingt line when the device is inoperation. .1 r

In the drawings accompanying this application: 1 n a Fig. 1 shows an embodiment of my invention in elevation;- 1 1 'Fig. 2 is a section onthe line22 of Fig.1 showing the details of construction' of the latching 1nechanism; x

. Fig. 3 is a section on the line of of a modified embodiment of the invention.

1 Befer'ringto the-drawings in detail; 1 designates a mast which, aswill be understood, is rotatable about a standard, a boom Q'being pivotally carried by the mast. 3 designates a hoisting cable which passes over a sheave 5 ontheouter end of the boom 2, this hoisting cablecarrying' hook 8 for attachment to the load, and a counterweight 9. j The cable passes about a sheave 6 on the mast and downwardly to driving mechanism, not shownfr .Y'

7 indicates the holding line; This line passes" about the sheave 5 for instance or another sheave onthe boom 2, and one end is broughtcinwardly and attached to the mast as shownat' l. The other end is securedto the latching mechanism constituting the subject matter (if-this application.

11 designates a shaft on which is rotatably Fig. (11S a se'cttionlon the line-H of 2 mounted, a'cable drum 12'. *The end1'3 of the bearing .17 .for receiving the shaft 11, the other bearing for the drumbeing provided in part by an end member 18 removably secured in the end of the drum-by 'bolts 19. Lubricant is supplied to the bearings 17 and the bearingQO by'oil channels 21 and 22, respectively; 1 p l The interior of the drum 12is much larger in diameter than the shaft 11, to provide between theshaft and the drum wall a space 23 for the reception" or takegup spring 24.

This spring is in the form of' aflat spiral,

and in order that thesame may be passed to the interior of the drumthe latter is provided with a slot 25 in itspe'riphery; The inner end 26 of the spring 24:has its temper drawn for a distance of two or three inches and is passed into the drum through the slot 25therein to a: slot 27 which is milled in the periphery of the shaft 11, the ends of this spring-receiving slot. 27 being curved: as

shown at 2'8 and 29 for apurpose to be hereinafter pointed out.

One end of the shaft 11 is squared or otherwise formed out of round as shown at 30 and after the end 26 of the spring is inserted in the slot 27 a wrench is applied to the end 30 of the shaft and the same rotated so as to draw the spring 24 into the drum and wind the same about the shaft 11, the inner end of the spring bending around the shaft as shown. The shaft is held after adjustment by set screw 30 which engages the shaft as shown in Fig. 2. The outer end of the spring 24 is then bent over the edge of the slot 25 in the drum as shown at 31, the periphery of the drum at this point being provided with a depression 32 for receiving the end of the spring so that the spring lies flush with the surface of the drum. By this construction both ends of the spring are securely anchored, the inner end. being anchored to the shaft while the outer end is anchored to the drum. H

Below the drum 12 and slightly to one side thereof a shaft 33 is provided, this shaft extending parallel to the shaft'11 and carrying at one end a pawl 34 cooperating with the ratchet teeth 14. On the other end of the shaft 33is mounted a pawl 35 cooperating with the teeth 16 on the upper end of the drum 12 as viewed in Fig. 2. The ratchet teeth 14 and 16 are disposed slightly offset with respect to each other, so that with the pawl 34 in engagement with one of the ratchet teeth 14 the pawl 35 is slightly out of engagement with the corresponding tooth 16 on the drum. This is shown at 36 in Fig. 4 and such a construction is employed for safety purposes inasmuch as normally the pawl 34 sustains the load, but should the pawl or tooth be fractured for any reason, the load will then be supported by pawl 35 and ratchet tooth 16.

In order that the pawls 34 and 35 may be moved to inoperative position to permit of the drum 12' rotating in a clockwise direction as viewed in Fig. 1, the shaft 33 is provided with a short lever 37 operated by a hand rope 38, and with a short lever 39 to which is attached a rod 40 carry ng a spring 41 and at its outer end a nut and, washer 42, the spring 41 lying between the nut and washerand boss or eye bolt 43 on the side of the mast.

, When the hand rope 38 is pulled clownwardly the shaft 33 is rocked clockwise, as

viewed in Fig. 1, and the pawls 34 and 35 carried out of operative position. Upon release of the hand rope the spring 41 returns the pawls to position to engage a ratchet tooth 14.

As above mentioned, one end of the holding line is fastened to the drum 12. This construction is shown in Fig. 3, from which it will be seen that the drum is provided with a bore 44 for receiving the end of the cable, this bore at its upper end as viewed in Fig. 3 being rounded off as shown at 45 so that sharp bends in the cable 7 are prevented. The bottom of the bore may be enlarged as shown at 46, and the strands of the cable opened up and the whole space filled with zinc or other suitable material, so as to per ma-nently and rigidly attach the cable end to the drum.

In winding or laying up the cable on the drum it will be understood that the drum is rotated anticlockwise and to insure that the cable will be laid on properly the flange at the cable attaching end of the drum is provided with a cam surface 48, which is so shaped as to cause the cable to travel upwardly as viewed in Fig. 2, that is to say, away from the flange atthe cable-attaching end of the drum.

It will be understood from the foregoing that when the pawls 34 and are released the boom 2 may be lowered this lowering of the boom placing the spring 24 under increased tension so that at all times there will be sufi'icient tension in this spring to take up the slack in the holding line or cable. It will be understood furthermore that this is the only function of the spring 24, the spring not being used to raise the load but merely to take up the cable 7 and to hold the load line against paying out except when desired.

The method above described of incorporating the spring 24 within the drum 12 of advantage in this type of apparatus in that it enables the maximum amount of sprmg to be used, a desirable feature in hoist- 111g apparatus of this character. It also enables a spring of maximum width to be employed.

By providing the removable end 18 for the drum, assembling as well as taking down of the apparatus is facilitated inasmuch as it is merely necessary to remove this end member whereupon the spring and drum may be pulled off the shaft or the shaft pushed out of the spring and drum, thecurved end 29 of the slot 27 which receives the inner end of the spring facilitating removal of the spring out of the slot or depression.

It will be apparent. also that this con struction provides for attaching the holding line to the drum in a very easy and effective manner and yet by providing the cam face 48 on the drum flange proper laying up of the cable on the drum when the device is in operation is assured.

The safety feature provided by the offset ofthe ratchet teeth 14 and 16 may be modified as shown in Fig. 5. In this figure it will be seen that the ratchet teeth 16 have been eliminated and that the drum in this instance is provided with only. the one set of teeth 14, the pawl 34 and operating mechanism therefor remaining unchanged. It will be seen,

' however, that one of the brackets 47 by which the shaft 11 is supported which lies adjacent the end 13 of the drum 12carries a pawl 48 adapted to engage the ratchet teeth 14, this pawl eingso positionedthatwhen the pawl 34 is in engagement with a tooth 14 pawl 48 will have a slight clearance between its end and the adjacent tooth 14 at the same end of the drum, so that if for any reason the pawl 34 should fail the load will be taken care of by pawl 48. To provide for freeing or unloading the pawls 34 and 48 simultaneously a tie rod 49 joins the arm 39 to anlarm 50 which is integral with the pawl 48 so that when the hand rope 38 is pulled downwardly to rock the pawl 34 to the right, the pawl 38 will atthe same time be moved to the left and the drum thereby be freed for rotation.

It will be understood that various changes may be made in the details of construction above described within the purview of this invention. What I claim is v s In hoisting mechanism latching mechanism for holding a boom in any desired position and comprising .a shaft, a drum rotatable relatively thereto, and pawl and ratchet mechanism for preventing rotation of the drum relatively tosaid shaft, said so pawl and ratchet mechanism comprising two sets of ratchet teeth one at each endofthe I drum and a pair-of pawls, one pawl cooperating with one set of teeth, the other with I the other set of ratchet teeth, said sets of pawls and ratchet-teeth being so disposed relatively to each other that in the event of one set becoming inoperative the other hecomes operative to prevent rotation of the drum relatively to the shaft. V as This specification signed this 18th day of- May, 1929. I g V CHARLES G. WRIGHT,

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