DE2107112A1 - Pulse-shaping element for impact tools - Google Patents

Description

Dr. A. Menfzs! Feb 9, 1971

pUns. W. Dahlka ed. / R.

Patent attorney
Refratk bsi Cologne

Celestial 137

GARDNER-DENVER COMPANY Quincy, Illinois 62301 (USA)

"Pulse-shaping element for impact tools"

It is known that basically all layers of earth or rock to be penetrated by local collapse or crumbling a force deflection characteristic into the borehole or show stiffness. It was found (XJS patent Mr. 3 382 932) that by arranging a so-called spring element into a rock percussion drill on the strata of the earth a force impulse can be transmitted, which in a

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• more desirable energy transfer to the layers and as a result results in greater penetration rates. This spring element preferably has a stiffness characteristic which is equal to the effective stiffness of the layer to be penetrated and which develops a force impulse that creates a shape if it is represented graphically as a function of time, which also results in a lower level of stress for the Drill rods and the coupling parts provides.

According to this knowledge, the required dimensions result such an element to form the force impulse for the Most rock percussion drills have an element in the form of a weak tab on which the hammer drill steps. The well-known, The spring that forms the pulse is completely in the drill housing arranged and thus extends the drill construction. However, such an extension is undesirable as it affects the drill makes it much heavier, unwieldy and bulky. It also makes this for rock drills that are mobile on an elongated Feed carriers are arranged, a longer and heavier carrier is required. On the other hand, it becomes the drill carrier not extended, is the effective feed length of the carrier and it must be shorter for deep drilling Drill extension pieces can be used. This makes again-

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around a more frequent attachment or removal of the extension r pieces required and thus takes more time to drill a borehole.

That the element that forms the impulse itself is highly valued and thus tends to fail, a sudden, unexpected occurrence can occur with an element lying completely in the housing Failure to destroy the drill, which in turn requires a considerable amount of time, since the drill itself has to be completely removed.

The invention aims at an element which forms the force pulse for an impact tool, in particular a rock drilling machine or the like driven by a pressure medium. to provide which comprises a separate rod or corresponding section in a one-piece drill rod. According to the invention forge see the power pulse shaping element {which in one end of a percussive rock drill in schlagaufnehmendem relation to a back and forth moving hammer member is interchangeably used. This rod, which forms a force pulse, can be provided at the opposite end with devices which are used for the releasable coupling of this element with a force-transmitting device, which comprises one of several,

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with the ends coupled together parts existing drill pipe and omitting a drill bit penetrating a layer of earth. The force pulse forming element according to the invention however, it may also comprise an area formed integrally with a drill rod when this drill bit is used for drilling used by holes that do not require extension pieces.

Contrary to the knowledge that is obtained when using the known elements that form a force pulse is, the invention provides an element that acts as a torque transmitting coupling for rotating a hammer drill rod can be used.

The invention thus improves the known element forming a force pulse in such a way that it can be used in conjunction with conventional rock percussion drilling machines can be used without changing the design of this machine itself must, whereby much higher penetration rates and a longer life of the drill string can be achieved. By Inserting such an element designed as a rod or as an integral area of the drill, it is not necessary To extend the drill housing, as is the case with the

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kannteil element of the F ^ ¹ Il was. Thus, the weight is also not increased and the bulkiness of the construction of the drill is increased. In addition, by inserting the rod that forms a force pulse in the drill string, its length is increased so that boreholes can be drilled in a single pass both with mobile drills and with lighter hand tools. Another advantage of the element according to the invention is that if the element fails, the rod according to the invention can be replaced quickly. In the event of an unexpected sudden failure, the drill itself cannot be destroyed, as was the case with the known element.

The drawing shows exemplary embodiments of the subject of the application shown. In this drawing show:

Fig. 1 is a partially sectioned side view a rock percussion drill operated with pressure medium with an inventive measure a force pulse forming element;

Figure 2 is a section along line 2-2;

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Fig ;. 3 is a side view of a mobile rock drill on a smaller scale and FIG.

Pig. k is a side view of a one-piece drill string with a drill head.

According to the invention there is an element which forms the force pulse or a so-called spring for a rock percussion drill operated with pressure medium from a separate rod. The essential Features for determining the stiffness characteristic and the de-dimensioning of the rod can be found in US Pat. No. Wr. 3 382 932 can be taken. Though a such rod element according to the invention in each usual with Pressure medium operated rock drilling machine can be used, the invention is based on a hammer tool described, in which repetitive impacts are exerted on a force-transmitting device.

In Fig. 1 of the drawing, a rock percussion drill is designated as a whole by 10. The rock drill is well known and

^J , J

comprises a housing 12 with a cylindrical bore 14 in this. A hammer part 16 arranged in this bore 14 is alternately in the chambers 18 depending on one

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or 20 in the bore 14 directed pressure medium, for example Compressed air can be moved back and forth quickly. A valve 22 controlling the pressure medium forms one end of the bore 14 and can receive pressure medium from a line (not shown) and alternately the chamber 18 or the chamber 20 feed in a known manner. The drill 10 further includes a

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Drive device 24, which is in drive connection with a

rotatable chuck 26 by a drive shaft 28 and a toothed

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wheel 30, the latter in teeth 32 on the chuck 26

intervenes. This chuck 26 is rotatably arranged in the front part 42 of the drill housing 12 ". The chuck 26 comprises a tight fitting sleeve 34 which non-rotatably carries a part 36 by means of complementary springs 40" and hats 38 in the area 39 of the part 3J (FIG. 2). . The part 36 can pass through the opening 43

be inserted interchangeably in the chuck 26 and is in

this chuck by a holder 44 set.

The part 36 is known as a shaft in rock percussion drills. The shaft 36 primarily constitutes the end regions H one force-transmitting device, which generally comprises one or more long rod-like elements, which by Threads are coupled with their ends together to form a:

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Form drill pipe. Furthermore, dex shaft 36 comprises an end

surface 46 that can absorb blows from the hammer part 16. Further For example, the shaft 36 can be viewed as a torque transmitting element that provides rotational movement to the drill pipe transmits to rotate a rock drill head located at the opposite end of the drill string.

In order to simplify the handling of the drill 10 and practically increase the length of the drill rod through the addition, the shank J6 is designed so that it does not protrude beyond the front end 42 of the drill housing more than is necessary to form the coupling thread 48. The shaft "} 6 comprises an elongated area 50" which is preferably located between the shoulder 52 adjacent the thread 48 and a collar 54. This collar comprises an area which cooperates with the device 44 ^ "to prevent inadvertent detachment of the shaft from the To prevent lining 26. The dimensions of the elongated region can be determined in terms of spring stiffness and cross-section, as described in US Pat. No. 3,382,932. The shaft 36 further comprises a flushing

y medium channel 36, which has a region 58 into which the flushing medium pipe 60 extends. Since the shaft 36 must in fact act as a compression spring, it is preferably off

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-S-

a highly resilient elastic material such as an alloyed steel or a titanium alloy.

In Fig. 3 of the drawing, a typical mobile rock drill is shown, which is designated as a whole with 62. This wheeled unit 62 comprises a crawler chassis 6k and an adjustable member 66 to which an elongated drill support

y ■

68 is attached. The drill 10 is arranged displaceably on the carrier 68 and can be moved back and forth thereon by suitable means not shown in the drawing. The drill 10 of this unit is provided with a drill string 70 comprising long drill rods 72 which are releasably coupled to one another and to the shank 36 by internal and external threads, the external threads k-8 being connected to internal threads 7 ^ on the rod 72, as Fig. 1 shows. The lower end of the drill string 70 carries a drill head 76 which has an earth

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Layer 78 penetrates to form a borehole 80 in response to the transmission of the impulse of force from the drill bit via the drill string 70. As can be seen in Figure 3, the lower end of the drill support 68 includes a guide 82 generally called a "centralizer" for the drill string. This guide 82 rotatably supports the rod 72.

- 10 -

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In Fig. K of the drawing, a one-piece shaft drill rod element is shown, which is designated as a whole with 86. This element 86 is generally known as a "single pass rod" and is used when sufficient drilling depth is achieved in a single stroke of the drill IO on the carrier 68. Such one-piece rods are also widely used in lightweight, portable rock drills used in underground mining. This element 86 includes a force pulsation forming transmission area 88 which is designed according to the teachings of the aforementioned American patent to provide a force deflection characteristic similar to that of the formation to be penetrated. The element 86 further includes a portion 90 which has grooves 92 and a collar 9 through which the element 86 can be inserted into a chuck 26 of the drill 10 in the same manner as the shank 36. The element 86 also has an end surface 96 against which the hammer part 16 - ^: acts, and also a spool medium channel 98 which leads to openings 100 in the vicinity of the drill head 102. As FIG. K shows, the drill head 102 is formed in one piece with the element 86, except for the exchangeable insert 1θ4. The end of the element "86 facing away from the drill head and interacting with the hammer part can, however, also have a beveled or threaded

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bearing area be provided in order to releasably connect a part therewith in a manner known per se. The element 86 can also be made of a material such as a steel alloy. The element can originally consist of separate Segments 90 and 106 consist, the latter being the Boring bar and the area 88 which forms a force pulse includes. The segments 90 and 106 can be molded and separately then be connected by so-called friction welding of the contacting surfaces 108.

A particular advantage of inserting the element forming a force pulse into the shank 36 or the one-piece shank drill rod element 86 can be seen clearly from the drawing, namely an effective extension of the drill rod, which is mainly located outside the drill 10. Each stroke of the drill f 10 downwards on its support 68 is limited by the impact of the front part of the drill housing k2 on the guide 82. If the element forming a force pulse were to be arranged entirely in the drill housing, the effective length of each stroke on the carrier would be shorter than it is with the element according to the invention, by means of which the length of the drill itself is increased. From the drawing it can also be seen that

12 -

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when a heavily loaded one forms a force impulse Element is damaged, this or the element 86 leiciit can be replaced.

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Claims (9)

Claims 1. A force pulse-forming element in an impact tool through which blows can be exerted, in particular on layers of earth or rock, and which has a hammer part that can be moved back and forth and a pipe rod consisting of a force transmission element or several of these elements with a drill head penetrating the layers of earth and by which the blows are transmitted from the hammer part to the earth layers, characterized in that the element (36, 86) forming a force pulse is connected in the drill rod (? 0) between the hammer part (16) and the earth layers, a shank part for said force transmitting members (72) and having a stiffness equal to the effective stiffness of the earth formation. 2. Element according to claim 1, characterized in that the shaft part (36, 86) has at one end an end surface (46 or 96) on which the hammer part (16) acts. 109887/0243 - i4 - 3. Element according to claims 1 and 2 for a striking tool with a housing and a chuck rotatably arranged in this, characterized in that the shaft part (36) is designed corresponding to the chuck (26). 4. Element according to claim "1 to 3» characterized in that the shaft part (36 ) comprises a torque-transmitting coupling between the impact tool and the linkage of force transmission members (72). 5 · Element according to claim 1 to 4 for a striking tool with a device for holding a shaft in the chuck, characterized in that i without t that the Shank part (36) one with said holding device (44) cooperating collar (54) comprises. 6. Element according to claim 1 to 5 »thereby ge - indicates that the shaft part (36) on the the end face (46) on which the hammer part (16) acts, an end facing away from the coupling of the force tuber tr agtuigaelemente (72) enabling thread (48). - 15 - 109887/0243 - -15 - 7. Element according to claim 1 to 6, characterized that the notch part (36) a lying between the collar (5 ^ 0 and the thread (48) Area (50) has one of the effective stiffness has the rigidity of the earth's stratum. 8. Element according to claim 1 to 7i characterized that the area (50) of the shaft part (36) in the case of an inserted into the striking tool Shank part is mainly outside of the tool housing (12). 9. Element according to claim 1 and 2, characterized that there is a shank portion (86) and an elongated member forming a drill rod (iOö) and that the shaft part (86) has a region (88) which is connected between the drill rod and the end engaging in the chuck (26) and one of the effective Stiffness of the earth's layer has corresponding stiffness. 109887/0243 Blank page