US1384051A - Lifting apparatus - Google Patents

Description

G. N. CRAWFORD.

LIFTING APPARATUS.

APPLICATION FILED lULY 2. 1917.

Patented July 112, 119216 2 SHEETS--SHEET l G; N. CRAWFORD.

unmc APPARATUS.

- AFPUCATION FILED JULY 2. I917. L38Q Q51 v Patented July 12, 192i.

2 SHEETS-SHEET 2.

GEORGE N. GRAVJ'FORD, OF CHECAGO, ILLINOIS, ASSIGNOB T FREDERICK C. AUSTIN, OF CHICAGO, ILLINDIS.

LIFTIL TG AYPARATUS.

esaosi.

Specification of Letters Patent.

Patented July 112, 1921.

Application filedJuly 2, 1917. Serial No. 178,137.

a citizen of the United States of America,

and resident of Chicago, Cook county, illinois, hare invented a certain new and useful improvement in Liftin Apparatus, of which the following is a specification.

lliy invention relates to apparatus of that kind in waich a swinging boom is employed, such as those on excavating machines, and especially those in which a drag-line-scraper or bucket is suspended from the end of the swinging boom, whereby a load of dirt or other material can be carried upward and swung around and dumped in the desired place.

' Generally stated, the object of myinvention is to provide a novel and improved construction whereby the raising and lowering of the boom may be controlled through the medium of a single hand-lever or other similar device, so that the boom and its load may be raised and lowered at the will of the operator.

it is also an object to provide certain details and features of construction and combinations tending to increase the general eihciency and desirability of a boom-controh ling or raising-and-lowering mechanism of this particular character.

To the foregoing and other useful ends, my invention consists in matters hereinafter set forth and claimed.

In the accompanying drawings Figure l is a side elevation of a drag-line scraper-excavating machine embodying the principles of my invention, showing one end thereof broken away for convenience of illustration.

Fig. 2 is an enlarged top plan view of the winding drum mechanism. and hand lever therefor by which the raising and lowering of the boom is controlled at will.

Fig. 3 is a side elevation of said mechanism.

its thus illustrated, my invention comprises a frame or body A, of any suitable character, mounted upon a turn-table B, whereby the body is adapted to swing about the vertical axis provided by the pivot Z), the body being supported by wheels at on said turntable. The turn-table, it will be understood, is supported at one end of the machine by the traction-devices G which, as

shown, are in the nature of caterpillars, and

by wheels or other supporting elements at the other end of the body, or by similar trac tion-devices. upon the end of the body, so that the outer end of the boom may swing up and down about a transverse axis at its lower. end. The hoisting cable or line E is wound upon a drum l mounted on the body to rotate in bearings f, and is supported by a sheave G at the outer end of the boom, the end-portion of the line being looped around the swinging sheave g and then brought upward and fastened at l to the outer end-portion of the boom. The sheave g is carried by a block 2 which is pivoted at 3 to the upper end of the bail at of the drag-line-bucket or scraper H, which latter is of any suitable character and provided with a drag-line 72, that leads around the sheave 5 at the base of the boom. and which extends to the smaller diameter 6 of the previously mentioned winding drum. This line /L leads around a sheave 7 on the upper portion of the bail 4 and then downward to its point of attachment 8 on the front end of the bucket. A hitch 9 extends between the front end of the bucket and the clamp 10 on said line, and the bucket is provided with stops 11 against which the bail 4L will bear while the bucket is being tilted, at which time the hitch 9 sustains the draft or pull on the dragline, the hoist-line E being slack. l V hen the bucket is hoisted with the load therein, a pull is maintained on the line It to keep the buck t in carrying position, but after the bucket is raised, and as soon as the pull on the drag-line h is relaxed, the front end of the bucket, will then tilt downward, inasmuch. as the portion of the line h whichextends around the sheave Twill not be taut. The pivotal points 12 for the bail l, on the sides of the bucket, are nearer the rear end. of the bucket, so that as soon as the pull on the line it is reversed, so'that the line becomes slack, the heavy front end of the bucket then tilts downward and discho. the load.

The boom D is supported by a ing sheaves 14 for the line 15 which extends around the sheaves 16 on the upper p0rtion of the super-structure ll of the body. Said line 15 has one end fastened at 18 to the boom, then passes over one of the sheaves 16 and out and around one of the sheaves 14, then back and around another sheave 16, then outward and around another sheave 14, then back and around another sheave 16, then outward and around another A boom D is pivoted at (Z.

sheave 14, and then back and around anothersheave 16, and back to the winding drum 1 on the body, which drum is supported on a shaft 2' in hearings on the body-frame. The shaft f has a relatively large gear-wheel 19 which engages the pinion 20 on the shaft i, whereby the two shafts rotate in opposite directions. The shaft 1' is provided with a clutch-device J, of any suitable character,

such as an ordinary friction or band clutch, for connecting the shaft with the drum 1, when the raising and-lowering line 15 isto be wound thereon, and vfor releasing said drum when this line is to'be paid out or unwound; A rock-shaft K is mounted on the body-frame, parallel with the shaft 71, adjacent thereto,

and provided with an arm 70 which is connected by a rod 21 with the bell-crank 22, which latter is suitably supported on the body-frame to oscillate about a vertical axis. The clutch J is controlled by a fork 23 which is pivoted on the bodyfi'ame at 24, and which has its lower end connected by a rod 25 Withthe otherendportion of thebell-crank 22, whereby the rocking of the shaft K, by meansof the hand-lever 26 at one end thereof, will tighten and release said clutch.

is closed, so that the drum This shaft K is also provided with an arm 24' which 1skeyed thereon, and which has a connection, 28 with one end of thebandbrake Lwhich is applied to the other end of the drum 1, whereby the drum can be released from the shaft e' and thereafter held against'rotation by the unwinding of' the line 15'under the weight of the boom. The other end of this hand- .brake L is anchored at Z, upon any suitable partof the body-frame. s

When the hand-lever 26'is in the position shown in full lines in Fig. thecluteh J I is locked to the shaft 6, and the band-brake L is released.

. vh th hand-lever is thrown into the po- 7 be slightly released to allow the boom D to swing downward by gravity, under the full I 7 control of the operator, and as soon as the boom is in the desiredposition the lever is then pulled back into the position at 30 to tighten the brake on the drum. W hen it is desired to again lift the boom with its load,

the hand-lever is pushedinto the position shown in full lines in Flg. 3, which closes the clutcl'nleavinp the band-brake released.

The shaft 2', it will be understood, is rotating constantly, being connected through the gearing l9 and 20, and other gearing of any source of motive power mounted on the body. The rotation of this shaft 2" is, of

suitable character, with an engine or other i course, in a direction to wind the *lin'e15 on the drum 1, when the clutch J is opera ated, so that the drum is keyed to the shaft, and the drum and shaft rotated in opposite directions when this line is unwound to permit downward movement of the boom.

It will be understood, of course, thatthe .orum 1?,01 drums, on the shaft are also driven from said source of power, and controlled by clutches or' brakes in any su table, or desired manner.

vVith the foregoing construction, it will be seen that the raising and lowering of the 'boomD is controlledbyithe single hand-V lever 26, so that the boom and its load can be raised and lowered at will by simply;-

the boom can be raised and lowered. and

,manipulating this single hand-lever. Thus, 7

controlled like that of a crane, when crane service is desired, and this advantageous centrol is obtained without reversing the engine or motor from whichfthe power is derived, Any suitable means can be employed for holdingthe lever 26 in one or more of its different positions. For example, a plate M can be mounted on the bodyframe to engage the lever, to hold the, latter plate N can be secured tothe edge of the body-frame to cooperate with the plate M' to hold-the lever in the position indicated at 29, but not in the position which the in the position indicated at 30, and alonger lever must assume to close the clutch. It

will be understood that said lever 26 can be flexible enough to permit slight outward moveinent thereof, to disengage it. from said plates, andso that it'may be swung freely iaclc and forth by the operator. The clutch J, being a friction clutch or band clutch, og'icrates gradually, so to speak, and does not suddenly lock the drum T to the shaft 1?, but provides a frictional connection be tween the drum and the shaft, so that some slippage takes place before the drum is finally connected to-rotate. in unison with the shaft, and in unison with themovable clutch section 7' which is splined on the shaft. The brake L operates in a similar manner, so that the frictional breaking ac tion is gradual, andin this way the drum T is subject to frictional action by the clutch Y i to rotate the drum in adirection to raise the boonn'and to frictional action by the brake to hold'the boom in raised position, and

with the combination of thesetwo frictional devices the drum is und'er full control and can .be rotated in either direction at the will of the operator, or held against rotation, depending upon the character of the work to be done. A ratchet O can be applied to one end of the drum I, to lock it against reverse rotation after the boom has been raised, if such is desirable or necessary, it being understood that this ratchet can be provided with a dog or pawl which can be manipulated by hand to throw it into or out of action when desired. With this combination of friction brake and friction clutch, under the control of a single lever, the lifting apparatus can be used in different ways, for different purposes, and has the essential requirements of a crane. The raising of the boom will bring the load closer to the body-frame of the machine, while the lowering of the boom will swing the load away from the machine, and with the arrangement whereby the boom is adapted to swing around sidewise, it is evident that a load can be picked up at any point and thereafter put down at any other point within the range of movement of the boom.

What I claim as my invention is 1. In lifting apparatus, instrumentalities to carry the load, line to raise and lower said instrnmentalities, a winding drum for said line, a clutch for rotating said drum to raise the load, a brake for said drum, means to swing the load sidewise, a single lever connected to control both the clutch and the brake, so that the load may be raised or lowered at will by operation of said single lever. a shaft on which said dr m and clutch and brake are supported, the clutch being operable to connect the drum to the shaft by movement of said lever in one direction, and adapted to release the drum when said lever is moved in the opposite direction to apply said brake, whereby the drum is retatable with the shaft to raise said instrumentalities and rotatable in the opposite direction on the shaft under control of said brake to lower the boom.

2. In lifting apparatus, instrumentalities to carry the load, a line to raise and lower said instri'imentalities, a winding drum for said line, a clutch for rotating said drum to raise the load, a brake for said drum, means to swing the load sidewise, a single lever connected to control both the clutch and the brake, so that the load may be raised or lowered at will by operation of said single lever, the connection from said lever to the clutch and brake including a rock-shaft arranged parallel. with the drum and having one connection with the clutch and separate connection with the brake.

3. A structure as specified in claim 1, ineluding a rock shaft connected separately to the clutch and drum and forming a support for said lever.

4. The combination, in an excavator, of instrumentalities to carry the load, a line to raise and lower said instrumentalities, a winding drum for said line, a clutch for rotating said drum to raise the load, a brake for said drum, means to swing the load sidewise, a single lever connected to control both the clutch and the brake, so that the load may be raised or lowered at will by operation of said single lever, a shaft extending through the drum and clutch, and means to rotate said shaft.

5. In hoisting apparatus, the combination of a winding drum, instrumentalitics operated by said drum, a friction brake associated with said drum, a clutch associated with said drum, a horizontal shaft for said drum, said clutch controlling the transmission of power from the shaft to the drum, a horizontal rock-shaft arranged parallel with said drun'i-shaft, a connection from said rock-shaft to said friction brake, a separate connection from said rockshaft to said clutch, whereby operation of the rockshaft in one direction will open the clutch and ti 'hten the friction brake while operation of the rock-shaft in the opposite di-- rection will loosen the friction brake and close the clutch manually controlled means for operating said rock-shaft in either direction to control said instrumentalities, a bucket connected to be raised and lowered by said drum, and means to swing the bucket sidewise.

6. A hoisting apparatus as specified in claim 5, said means comprising a single hand-lever secured to said rock-shaft, the clutch connection being disposed between said hand-lever and the other connection to the brake.

'7. .1 hoisting apparatus as specified in claim 5, said manually controlled means comprising a hand-lever, and locking means to engage the hand-lever, the said hand-lever having one position in which it is locked against movement in either direction, and another position in which it is locked against movement in one direction, and another position in which it is free to move in either direction.

9. In an excavating machine, the combination of a body mounted on a turn-table, a boom pivoted on said body to swing up and down, devices including a winding drum to raise and lower said boom at will, a drag line bucket. a hoist line to support the'bucket on the boom, a drag line by which to pull the bucket toward the excavator body, means to operate said drum, and means to operate said hoist line and dragline, said devices including a single hand lever having a plurality of positions and a brake and a clutch both of which are controlled thereby to control the raising and lowering of the boom at will.

Signed by me at Chicago, Illinois, this 16th day of June, 1917 GEORGE N. CRAWFORD.

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