DE1484454B1 - EARTH DRILLS FOR UNDERCUTTING DRILL HOLES - Google Patents

Description

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The invention relates to an auger ..... 15, and. so that the flaps 13 fixed in a position Undercutting of boreholes with a hold, in which the lower part 10 is closed. Allow cylindrical lower part open at the top as collecting holes 17 in the wall of the lower part 10 container for the cuttings and symmetrically around a loosening of the pawls 16 by introducing a the vertical drilling axis on a superstructure 5 lever or pin that arranged the ends of the pawls Flocks which in essence lifts. The hinged edges of the flaps 13 are kalen levels slightly bent between a closed position so that when the flaps 13 are free and a working position are pivotable. hang downwards, they are not completely perpendicular

In known auger bits of this type, it had to be able to occupy one another, but rather loosened soil for the most part (USA.-Patent io diverge downwards. This is sure-2 697 582) or completely, be rotated, so that, provided that the flaps 13 are there simply and safely there was considerable friction on the ground, and one that can be closed and locked by that Considerable part of the effort for the with the drill on the earth or the bottom of the drilling turning of the earth had to be used. hole is placed.

The invention is therefore based on the object 15 At the upper end of the bush 11 is a bearing 18

to avoid this effort. The solution to this provided with a brass washer 19, and

The object is according to the invention that the upper part of the bearing 18 carries a vertical) inner

cylindrical collecting container rotatable via a bearing hollow shaft 20, which has a square cross-section

with the upper construction supporting the shares. A central stand 21 with upper and lower

is bound. ao bearing is located within the inner hollow shaft 20

The superstructure rests on a thrust bearing and is used to lower the superstructure.

of the cylindrical lower part and can be held from a right to the cylindrical lower part 10. Above

Support part and consist of an actuating part, the upper part of the inner hollow shaft 20 can be a

axially movable relative to the cylindrical lower larger hollow shaft 22 slide, which also have a

part and the support part is. 35 has a square cross-section, and at the top

The bottom of the cylindrical lower part is part of a short head cylinder 25 .befestigt, .. its

preferably by at least one movable diameter equal to that of the cylindrical lower part

Flap formed with means that is 10. The upper part of the outer hollow shaft 22 carries

Flap or flaps releasably in the closed position a coupling 24 for coupling with the lower

to keep. The flaps can by automatically 30 end of a known driver rod or their

working quick release fasteners are held, clutch. Two parallel pivot pins 25 are

for example, spring-loaded latches. symmetrically across the head cylinder 23 at its

Ofmais it is desirable to be attached to the bottom of the drill inside and pivot two

loches immediately before the introduction of the concrete sheet steel sheets 26, which through on their undersides

To clean up small pieces of loose material to 35 arranged ribs 27 are stiffened. Each flock 26

remove that is there during the drilling process has a straight leading edge that is perpendicular to

may have accumulated. For this purpose the pivot pin 25 can run, and a drawn one

nen in the bottom flaps radially extending slots edge, which from the other end of the pivot pin 25

be provided. is curved towards the outer end of the leading edge.

An embodiment of the invention is shown in 40 The shares 26 are from the leading edge to the hand the drawing explained in more detail. It represents a drawn edge curved inwards, so that at

F i g. 1 the side view of an auger after rotating the superstructure in the direction of the guide

of the invention partially in section, the flocking edge (as shown by the arrows in F i g. 4)

are swung out in the working position, the curvature of the shares 26 the overburden on the

F i g. 2 a section through an individual part of the center of the tool and thus in the cylindrical

F i g. 1 along the line H-II in FIG. 1, drical lower part 10 clears. Parallel to and near

F i g. 3 a fig. 1 corresponding view, with each coulter 26 bearing a deep one at the leading edge

the shares in the closed position an inwardly extending stiffening rib 28, and a

are pivoted, piece of angle iron 29 is between the stiffening

F i g. 4 shows a section along the line IV-IV in 50 rib 28 and the leading edge of the coulter 26.

Fig. 1, ordered and extending from the outer tip

5 shows a section along the line V-V in the coulter 26 up to near the pivot pin 25. With

Fig. 3. The angle iron 29 is a flat cutting pawl 31

A narrow, hollow, cylindrical lower part 10 is bolted, the outer edge of which is a straight cutting edge sits a short, central, axial sleeve 11, which is formed with 55, which is slightly above the leading edge the coulter 26 protrudes from the cylindrical lower part 10 by means of struts 12. Holes 32 that run along the is bound. The lower end of the lower part 10 is angle iron 29 drilled into the coulter 26, made possible by two semicircular flaps 13 closed an access to the bolts, which the sen, which hold the cutting pawl 31 in an articulated manner with the aid of two radial bolts 14, so that the cutting pawl 31 are connected to each other, the radial BoI-60 can easily be replaced. The cutting pawl 31 is zen 14 arranged between the side walls of the lower part 10 so that they are approximately perpendicular to the conical and the bushing 11 extends on the common see-through surface which when the drill is actuated knife of the flaps 13 are attached. Which is cleared out. At one point, roughly close Top of each flap 13, near the arc of a circle - the center of the leading edge of the blades 26, are in the middle, a hook 15 is attached, while spring-loaded steel rockers 33 are hinged to the load hook-shaped pawls 16 around horizontal stiffening ribs 28. The other ends of the Schwin bolts pivotable on the inside of the cylindrical 33 are at the lower end of the inner hollow shaft see lower part 10 are arranged, hinged to the hook 20, immediately above the thrust bearing

18. The connection point of the steel rocker 33 to the coulter 26 is approximately the same distance from the Tip of the coulter 26, the pivot pin 25 for the coulter 26 and the other pivot point of the steel rocker 33. This ensures that the tip of the flock 26 is on an approximately horizontal path moved outwards.

The upper end of the cylinder 34 of a hydraulic jack is near the lower end of the outer one Hollow shaft 22 is articulated, and the lower end of the piston rod 35 of the lifter is on a steel rocker 33 hinged. Oil lines 36 lead the oil from the jack to a small sump 37, the (Fig. 4) is arranged within the head cylinder 23. A throttle valve, not shown, in the return line allows an optional change in the speed of swinging out of the steel rocker 33 and thus the speed of the advance of the shares 26.

In operation, the auger is with the lower end of a known driving rod over a Coupling connected, which engages the upper end of the outer hollow shaft 22 of the upper structure. Of the Auger hangs so on the driving rod, and the inner hollow shaft 20 hangs on its lowest Position with respect to the outer hollow shaft 22, as in F i g. 3 shown. The upper ends of the flocks 26, which are hinged in the head cylinder 23, are pulled up, and the tips of the cutting pawls 31 are drawn close to the vertical drill axis and are in the closed position.

In this state, the drill is inserted into a pre-drilled cylindrical hole of the appropriate diameter inserted, and then the drive rod is rotated. When the lower part 10 of the drill When it reaches the bottom of the borehole, it lies on the ground and the top structure of the drill moves on the thrust bearing 18 to. The torque is taken directly from the drive rod through the head cylinder 23 transferred to the shares 26. As the drive rod is lowered further, its weight pushes on the outer hollow shaft 22. Additional pressure is still exerted when the advance of the Driving rod is accelerated by forces. This causes the upper ends of the shares 26 pressed down, and the tips of the shares 26 begin their movement outward to the working position. As this movement progresses, the bottom of the borehole is cleared in the shape of a truncated cone. the spoil is cleared into the cylindrical lower part 10 by the shares 26. The movement of the flocks 26 is such that initially only the tips become effective, but then larger parts of the cutting pawls 31 are used. This results, together with the presence of the thrust bearing, a high efficiency of the auger and could lead to an over-rapid advance of the coulters 26 in soft soil, if this is not the case would be prevented by hydraulic dampers, such as cylinder 34 and piston 35. Within the The cutting speed is dependent on the drive rod in the limits set by the damper and can be controlled by this through the lowering speed.

The conical reaming of the bottom of the borehole is achieved by progressive cutting outwards causes, and the reaction force of the earth on the shares 26 helps the drill is always kept in contact with the bottom of the borehole. When the outer hollow shaft 22 their has reached the lowest position relative to the inner hollow shaft 20, the upper ends of the shares 26 are fully depressed and these are in their open position. The clearing of the bottom of the borehole is then ended.

Then the drive rod is raised, and the shares are thereby closed in their Position drawn. When the outer hollow shaft 20 has reached its uppermost position, the whole drill lifted out of the borehole and can then be in an unloading position over a mound or a Transport vehicle are brought. The overburden is poured out by the fact that the ends the pawls 16 are actuated through the holes 17 in the cylindrical lower part 10, so that the Flaps 13 open falling down. When all of the overburden has fallen out, the flaps can 13 by placing the drill on the ground or by lowering it again into the borehole are closed, with the diverging flaps 13 pressed into the closed position and be held there by the pawls 16. If the drill is set on the ground, it will be the shares 26 pushed out under the weight of the drive rod. However, this does not happen at excessive speed, due to the limitation of the speed of movement the hydraulic damper.

When the drill is raised again, the shares 26 are retracted and the empty drill can be reinserted into a borehole.

Claims (3)

Patent claims: 1. Auger for undercutting boreholes with a cylindrical open top Lower part as a collecting container for the drilling material and with symmetrical around the vertical drilling axis shares arranged on a superstructure, those in substantially vertical planes between a closed position and a Working position are pivotable, thereby marked. that the cylindrical lower part (10) via a bearing (18) rotatable with the the upper structure (20, 21, 22) carrying the groups (26) is connected. 2. Earth drill according to claim I. characterized in that that the bottom of the cylindrical lower part (10) has at least one hinged flap (13) which can be released by pawls (16) is kept in the closed state. 3. Earth drill according to claim 2, characterized in that that radial slots are recessed in the flaps (13). 1 sheet of drawings