US1999682A - Excavator - Google Patents

Description

April 3G, 1935. F. H. BAKKER EXCAVATOR Filed Deo.

/NVENTOR MMM Patented Apr. 30, 1935 laterz UNITED Fil-TME EXCAVATUR Frederik Hendrik Bakker, The Hague, Netherlands Application December 19, 1933, Serial No. 703,067

6 Claims.

This invention relates to a scraper or excavator bucket of the bottomless type which is drawn to and fro over the ground by means of several cables and the scraper bucket has means to regulate the depths ofexcavation in every point of the path during the working of the same. This device regulates the depth of excavation in a fashion similar to that set forth in my Dutch Patent No. 31,138.

When the excavator bucket is drawn forward during the working period the depth or extent of excavation can be regulated by the use of a rocking knife. This rocking knife can be placed in various positions vby the operation of several cables used with excavator buckets of this type'. These cables are operated -at different times in order to x the knife in its desired position. The cables are referredl to as steering cables, pulling cables and back pulling cables. When the bucket is full or when it is desired; to discontinue the excavationwith the` bucket, the steering cable is braked. The braking of this cable results in, a force being applied on the bucket contrary to the pulling force in the pulling cable and the resulting force on the bucket is equivalent to the pulling force in the pulling cable, minus the brakin g force in the steering cable. Since the braking force represents a loss of power, it is necessary, in order to have the device function as eiciently as possible, to reduce the loss of power to a minimum. p

It is therefore an object of this invention to reduce the loss of power to a minimum.

This is accomplished by the use of a rocking vknife which can be placed in diierent positions during the workingof the machine. This is done by the braking of the steering cable or the back pulling cable which causes the knife to move into its proper position notwithstanding the pressure of the earth on the knife which tends to force the same into another position.

It is further to be noted that the rocking knife may be locked in a number of intermediate positions as well as extreme positions which are not changed by the pressure of the earth on said knife. A The invention is set forth in the drawing which discloses two types of excavatorvbuckets. Figure l discloses a side view of a scraper bucket in which the digging knife may be placed in two extreme positions. Fig. 2 discloses a cross section of a steering coupling which may be used in place of the wheel shown in Figure 1 which allows the knife to be locked in several intermediate positions. Fig. 3 shows a longitudinal section of the steering coupling shown in Fig. 2.

The scraper bucket l is drawn over the ground during the working period of the device by means of a pulling cable 2. A U-shaped knife t having a cutting edge 3 is pivoted to said scraper bucket i atit, so that it can be placed in several digging positions. A connecting rod 'l is coupled by means of an axle F to the top end 5 of the knife 4. The opposite end of this connecting rod l is connected to a pin il whichis rigidly connected to a rotatable cable wheel 9. This cable wheel is movable around an axle lli, which axle is rigidly connected Vto the side plates il of the scraper bucket i. The steering cable i2 and the back pulling cable i3 areV connected to the circumference of the wheel 9 at various points to move the wheel in opposite directions. The ends of Y the pin move in circular slots in the side plates i l. These slots contain the ends l5 and IB which limit the extent of the movement of the pin 8 and therefore nx the extreme positions for the digging knife.

l The operation of this device is as follows: During the working period the back pulling cable I 3 is braked which causes the cable Wheel 9 to turn in a counterclockwise direction. The movement of the cable wheel 9 in a counterclockwise direction causes the connecting rod l' to move to the left and the knife l which is rigidly pivcted to said connecting rod falls forward and thereby allows the cutting edge 3 to dig intothe soil of the earth. This position of the cutting edge of the knife is indicated in Fig. I of the drawing by dotted lines. Y

l It may be desirable'during the working period to have the cutting edge of the knife withdrawn 'from the ground This is accomplished by braking the steering cable l2. The braking of the steering cable causes the cable wheel 9 and the pin 8 to move in a clockwise direction. This movement of the wheel and pin causes kthe connecting rod l to move to the right. This operation therefore causes the knife 4to fall backwards into a position as indicated in Fig, 1 of the drawing by full lines.

The radius of the circle made by the ,movement of the pin 8 mounted on the cable wheel 9 must be chosen in such a way that the pin passes for a short distance during the last portion of the rocking motion an imaginary connecting line of the points 'to iii. In its extreme positions the pin kpasses the dead points of this imaginary line and as a result it cannot be dislocated by pressure or tension in. the connecting rod This particular feature also allows the release of the braking force which might be made to the steering cable or the back pulling cable.

In case it is desirable to position the knife in intermediate positions, the cable Wheel is replaced by a steering coupling such as the device shown in Figs. 2 and 3. It is particularly desirable to place the knife in intermediate positions where` the excavation is made on a broken slope or is passed over thin layers of earth. In this steering coupling the axle l@ is replaced by a ratchet wheel il' which has teeth. The teeth of this ratchet wheel are positioned so that 'they point in a clockwise direction. The ratchet wheel is suitably connected tothe plates `Ii'of the scraper bucket by means of a Xed axle with key and keyway or, as shown in the drawing, by several bolts I8. Around the ratchet wheel I'I are formed circular running surfaces which are surrounded by two circular plates IS rigidly connected to cach other by means of the locks 2li, bolts 2i and 222 and the pin 8. The paWls 23 of the ratchet wheel construction have tail pieces Zilwhich can pivot about the bolts 22 and pin 8. These pavvls are ordinarily urged against the ratchet wheel il by means of the springs 25 whichmay be connected to the bolts ZI in the blocks 28. While the number of these pawls may be varied, the drawing discloses the use of only three.

Arpund the plates 49 previously referred to there is rotated the pulley ring 25 which has in its outer circumference cable grooves upon which are secured the ends of the steering cablev I2 and the backpulling cable I3. The ends cf these two-cables are wound around said ring in opposite directions so that the ring may be turned in a clockwise or counterclockwise direction, according to the desires of the operator. The amount of rotation of this ring 25 in relation to the plates It is limited by the cams 2l on the blocks 2d which cams alternatively push against the points 28 and 29 of the ring 2E.

The cams 3B are mounted on the inner surface of the ring 28 in order to push against the tail pieces 24 of the pawls 23 when the ring E@ is turned in a counterclockwise direction. If the ring is turned further to the left, the cam 3@ pushes the tail pieces 2li inwardlyv against the pressure of the springs 25 and moves the pawls 23 free from the ratchet wheel Il.

The operation of this type of scraper is as follows: When the bucket is pulled forward and no braking force is exerted on the steering cable or on the back pulling cable the soil of the ground pushes against the cutting edge 3 of the blade 4 and causes this knife to fall forward (see dotted lines of Fig. l). As a result of this, the connecting rod 'I and the pin 8 are pulled forward. During this movement to the left, or in a counterclockwise direction, the tail pieces 2e of the pawls Z3 become free from the cams 3o. After this movement the springs 25 press these tail pieces outwardly and rcause the pawls to be pressed Ybetween the teeth of the ratchet wheel il. This results in the placing of the knife'in a fxedvinterrnediate position which may not be changed by the pressure of the soil.

If it is desired to dig a deeper out in the ground the back pulling cable is braked. This causes the ring ZS to turn to the left and the earns SG to press the tail pieces 2d inwardly. This results also in the pawl becoming free from the ratchet wheel I1. Due to the tension of the connecting rod 'i caused by the pressure of the ground on the cutting edge 3 of the knife 4, the pin 8 is also moved to the left and this causes the tail pieces 24 to become free from the cams 30 so that the pawls 23 catch behind the teeth of,

the ratchet Wheel I'I. By continuous or'repeated manipulation of the device as herein mentioned, the digging knife can be made to fall forward in its extreme position.

It also might be desired during the operation of the device that there be no digging into the earth. This is accomplished by braking the steering cable which causes the ring 26 to turn to the right until the points 28 on said ring press against the earns 2i' of the blocks 2E). Upon further rnovernent of the rings 26 the blocks 20A and the pin 3 are moved to the right and the pawls slide over the teeth of the ratchet Wheel I'I. As soon as the braking force in the steering cable stops, the pulling force of the connecting rod fi pulls the pin 8 to the left until the pawls engage the teeth of the ratchet Wheel and lock the knife in a lfixed position such as shown in the full lines for the knife in Fig, 1 of the drawing.

When it is desired to pull the bucket backwards, the back pulling cable I3 first turns the ring 25 .to the left which results in the pawls 23 being lifted from the ratchet wheel I'I. The points 29 of the ring 26 then come into contact with the cams 21 and pin 8 which are likewise caused to rotate to the left. The rotation of the pin 3 to the' left is. accomplished against the pressure of the connecting rod 1 created by the pressure of the ground against the back side of the knife4 4. Asa result of this constant pulling force in the back pulling cable I3, the ring 26 and the pin 8 are turned into the eXtreme position whereby the knife is pressed into its forward extreme position so that the back side of the knife cannot dig itself into the ground.

y The detailed description above describes the invention proposedbut applicant desires it. to be known that his device may be completed-and operated by other types of mechanism.

What I claim is:-

l.. In a digging scraper bucket of the bottomless-type, cable means for moving said scraper over the ground, a digging knife pivotally mounted upon said bucket and means'for rocking said digging knife to several angular positions with respect to the horizontal and means connected with said rocking means for locking said digging knife in its desired digging position, all of said means being operable during the movement of the scraper bucket over the ground.

In a digging scraper bucket of the bottom- .less type, cable means for moving said bucket over the ground, a rocking knife pivotally mounted on said bucket, means for moving said rocking knife to several angular positions with respect to the horizontal, and means connected with saidrocking means forlocking said knife in its desired digging position, all of said means being operableduring the movement of the scraper bucket over the ground. Y

3. In a digging scraper bucket of the bottomless type, cable means for coming said bucket over the ground, a U-shaped digging knife pivotally mounted on said bucket, means for rocking said U-shaped digging knife to several angular positions with respect to the horizontal, and means connected with said rocking means for locking saidv knife in its desired digging position, all of said means being .operable ,duringv the movement of the scraper bucket over the ground.

4. In a digging scraper bucket of the bottomless type, cable means for moving said bucket over the ground, a digging knife pivotally mounted upon said bucket, an oscillating cable Wheel movable by a pair of cables for moving said knife into several angular positions with respect to the horizontal, and means connected with said cable Wheel for locking said knife in the desired digging position, all of said means being operable during the movement of the bucket over the ground.

5. In a digging scraper bucket of the bottomless type, cable means for moving said bucket over the ground, a digging knife pivotally mounted upon said bucket, means for rocking said knife into several angular positions with respect to the horizontal, and a paWl and ratchet mechanism connected with said. rocking means for locking said knife in the desired angular position, all of said means being operable during the movement of the bucket over the ground.

6. In a digging scraper bucket of the bottomless type, cable means for moving said bucket over the ground, a digging knife pivotally mounted upon said bucket, an oscillating cable Wheel movable by a pair of cables for moving the knife about its pivot into a desired angular position With respect to the horizontal, and a pavvl and ratchet means for locking said knife in said desired position, all of said means being operable whereby said knife may be moved into several different angular positions and locked therein during the movement of the bucket over the ground.

FREDERIK HENDRIK BAKKER..

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