US1553062A - Slewing gear for drag-line excavators, grab excavators, revolving shovels, and the like - Google Patents

Description

GRAB ExCAvAToRs SeptA 8. 1925. I

H BEDGooD SLEWING GEAR FOR DRAG LINE EXCAVATORS,

REVOLVING SHOVELS AND THE LIKE Filed July 10. 1924 2 sheets-sheet 14 GRAB ExcAvAtroR's Sept. 8, 1925.

2 Sheets-Sheet 2 Il im Patented Sept. 8, 1925.

UNITED STATES g VI-IU'BIRT OSWALD BEDGOOD, 0F GLASGOW,

SCOTLAND, ASSIGNOR TO LOBNITZ & CO'M- PANY LIMITED, OF RENFREW, SCOTLAND.

SIEWING GEAR FOR DRAG-LINE EXCAVATORS, GRAB EXCAVATORS, REVOLVING SHOVELS, AND THE LIKE.

Application led July 10,

To all whom t may concern.:

Be it known that I, HUBERT OswALD BED- ooon, of Beechmount, 14 Dalkeith Avenue, Dumbreck, Glasgow, Scotland, a subject of the King of Great Britain, have invented certain new and useful Improvements in Slewing Gears for Drag-Line Excavators, Grab Excavators, Revolving Shovels, y,and the like, of which the following is a specification.

This invention relates to drag line eX- cavators, grab excavators, revolving shovels and the like and has for its object to provide an improved slewing gear for the revolving platform or turntable carrying the jib of the machine.

At present it is usual to operate the revolving platform or turntable by means of a circular rack and pinion gear, the rack being fixed and the pinion being on the turntable and meshing with the rack and running round the same to rotate the turntable and slew the jib.

According to this invention the slewing is effected by meansE of a winding winch and drum mounted on the revolving platform or turntable of the machine the winding drum acting on one or more ropes which pass round and frictionally grip a stationary part of the machine.

A convenient embodiment of the invention will now be described, by way of eX- ample, with reference tothe annexed drawings which show only such parts of a drag line excavator as are necessary to enable the invention to be understood.

Fig. 1 is a side elevation showing the slewing gear and slewing engine of the eX- cavator.

Fig 2 is a plan view thereof. p

Fig. 3 is an end elevation of the gear and engine looking from the forward or jib end of the excavator.

Fig. 4 is a detail view showing the rope tightening gear and guiding sheaves with part in vertical sect-ion along the centre line of Fig. 2.

The drag line A and its fairlead B and part of the jibi C are shown merely to illustrate the relative positions of the parts.

The numeral 1 denotes the underframe mounted, as usual, for linear motion on rails. On the upper surface of this frame 1- is a circular roller race 2, concentric with which 1924. Serial No. 725,251.

butv of greater diameter is a circular frame 4 comprising twol superimposed channel bars 4a and '4b secured to the upper surface of the under frame 1. Two double sheaves 5 and 5a of equal. vdiameter are mounted in recesses inthe revolving platform 3 in a transverse vertical plane tangential to the aforesaid frame 4 at its foremost part. The spindle of the sheave 5 is placed slightly higher than that of sheave 5, the lowest points of the grooves of the two sheaves being in horizontal planes through the centre lines of 'the upper and lower channels, 42L and 4b respectively.V v

At the forward end of the frame 4 two openings 6a and 6b are formed, the former in the upper channel and the latter in the lower channel. Just inside the openings two coi-axial sheaves 7 and 7a are mounted on the frame 4 with their common axis sub-- stantially vertical.

A two-cylinder horizontal steam engine 8 is secured athwart the revolving platform 3. Through a coupling 9 and spur gear 10 the engine drives a winding drum 11 whose axis lies in the plane of the centre line'ofv the'revolving platform 3, its central transverse plane being in the plane of the sheaves 5 and 5a, hereinbefore mentioned.

Two jockey pulleys 12 and 12*1L are anchored to the under frame 1 within the frame 4, in the positions shown in Fig. 2 by screw coupling rods 13, 13a.

The wire rope X, by which the slewing is effected, is double and is endless. .Starting from the jockey pulley 12", Where the two plies of rope are separated and the said pulley inserted between them, the plies come together and are led round lone side of the upper sheave 7, then round the upper channel ring 4a in a counter-clockwise direction to the fore end of the frame 4 until they reach the opening 6a Vwhere the double rope passes outwards and leaves the ring in a tangential direction passing round the sheave 5 and thence round the drum 11.

From the drum 11 the rope passes on (to the left in Fig. 3), round the sheave 5a, whence it meets the lower ring 4b, round which it describes a complete` circle in a counter-clockwise direction back to the lower sheave 7 where it passes through the opening 6b to the inside of the frame 4. Here the two plies are again separated and the second ockey pulley l2 inserted therebetween. By tightening up the screw couplings 13, 13a securing the pulleys 12 and 12a any desired degree of tension may be placed on the wire rope.

When slewing the rope is wound in on one side of the drum and paid out on the other, producing rotary motion of the platform.

It will be apparent from the foregoing description that7 according to this invention, a very simple and effective method of slewing a drag line excavator jib is provided, whereby toothed gearing and the usual circular rack are dispensed with, the ifrictional grip of four plies of Wire rope being' substituted therefor.

ril'he invention also can be applied to grab excavators7 revolving shovels and the like.

Having now fully described my invention what l claim and desire to secure by Letters Patent is An apparatus of the character described including in combination, a stationary circular frame embodying superposed channel like members, pulleys within the frame, anchors for the said pulleys, each of' the said anchors including screw coupling rods, a winding drum, and an endless rope or cable, said rope or cable being doubled and passing around the said winding drum, the rope or cable on one side of the drum passing around the upper channel member of the said frame to one of the said pulleys, the rope or cable on the other side of the drum passing around the lower channel member of the said frame to the other of the said pulleys.

ln testimony whereof l affix my signature.

HUBERT OSfl/VALD BEDGOOD.

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