DE1255065B - Impact drill head for compressed air operated retractable hammers - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

E21c

German class: 5b-13/08

Number: 1255 065

File number: K 59924 VI a / 5 b

Filing date: July 30, 1966

Open date: November 30, 1967

The invention relates to a percussion drill head for compressed air-operated countersink hammers with in the area of Scavenging air channels formed on the outer drill head recesses for supplying the exhaust air from the end-face holes of the pre-cylinder to the drilling bottom.

There are already drill heads with a central suction system for cuttings known for hammer drill, in which the drill head with external recesses as well as with a central, inwardly widened channel with an elliptical cross-section for the suction of cuttings is. These drill heads cannot be used for air-operated machines because of the suction of the cuttings Sinking hammers are used in which the exhaust air of the sinking hammer pre-cylinder is used as scavenging air occurs.

Furthermore, percussion drill heads for compressed air-operated submerged hammers are already known, in which in the Drill head air supply holes are provided. When using such hammer drill heads on compressed air-operated Versenkhammem, whose pre-cylinder ao exhaust air is used as scavenging air, occurs the very considerable The disadvantage that these flushing air holes clog easily, especially when the hammer drill head penetrates a zone of softer, loamy soil. This clogging of the purge air holes is primarily disadvantageous because not only does it eliminate the need to blow out the cuttings, but above all the performance of the lowering hammer also drops suddenly, since the exhaust air from the preliminary cylinder is no longer can exit without resistance. There is a significant drop in drilling performance that may occur also only by cleaning the drill head after removing the drill rods back to the original Efficiency can be brought.

The object of the present invention is to provide a percussion drill head for compressed air-operated submerged hammers with scavenging air channels formed in the area of the outer drill head recesses for supplying the exhaust air to form from the frontal bores of the pre-cylinder to the drill bottom so that with manufacturing technology simple design in addition to a favorable alignment of the scavenging air ducts on the center of the Drill head work surface ensures that clogging of the scavenging air ducts is reliably prevented.

This is achieved according to the invention in that the over the entire length to the recesses Laterally open scavenge air ducts worked into the base of the recesses on their cutting edge side The mouth tapers in the shape of a funnel and converges towards the longitudinal axis of the percussion drill head are.

An advantageous embodiment consists in this of the hammer drill head

for compressed air operated submerging hammers

Applicant:

Richard Karnebogen,

Vollme (Westf.), Am Hang 3

Named as inventor:

Richard Karnebogen, Volhne (Westphalia)

according to the invention in that each longitudinal channel of two running at an acute angle to each other, air inlet side separated from one another by a knife-edge protruding, wedge-shaped gusset Holes is formed.

As a result of this configuration, a hammer drill head is created with a simple, robust design that even when used with corresponding compressed air-operated countersinking hammers regardless of the soil brings uniform drilling performance over long periods of time. Clogging of the scavenge air ducts is largely prevent. If a plug forms at the mouth of the scavenge air duct on the cutting edge side, so this does not reduce the performance of the lowering hammer; the exhaust air of the preliminary cylinder can according to the laterally open channels to evade to the side. The one who continues to work with the same performance Submerged hammer then immediately moves the plug formed from the cutting edge Mouth gone. The plug loosens due to the funnel shape of the scavenge air ducts as a result, in the scavenge air duct, the scavenge air may still reach behind and regardless of it Structure destroyed or removed. The funnel shape of the scavenge air ducts also accommodates the fact that the frontal bores of the pre-cylinder because of the wall thickness of the pre-cylinder certain Cannot exceed diameter; the funnel-shaped scavenge air ducts can extract the exhaust air from several Record holes on the face side. The funnel shape leads to an increase in pressure in the purge air in the direction of the mouth on the cutting edge side. The converging position to the longitudinal axis of the hammer drill head causes an extensive supply of the flushing air to the center of the drill head working surface. It it was found that despite the laterally open training and despite the funnel-shaped arrangement

^; 709 690 / +

Claims (6)

and converging position during normal operation it is always ensured that the drilling air emerging from the end-face bores of the preliminary cylinder reaches the bottom of the borehole. The creation of each longitudinal scavenging air channel through two bores running at an acute angle to one another while leaving a corresponding wedge-shaped gusset is advantageous in terms of manufacturing technology and with regard to the scavenging air flow. In the drawing, the invention is shown in an exemplary embodiment. It shows A b b. 1 shows a longitudinal view of the hammer drill head according to the invention, which is inserted into a pre-cylinder of a countersinking hammer, FIG. 2 shows a longitudinal section in this regard along line A-B in FIG. 1, A b b. 3 is a partial longitudinal view in the direction of arrow C in A b b. 1 and A b b. 4 a view against the end face of the hammer drill head. The hammer drill head 1 sits with its shaft 2 in the cylinder bore 3 of the pre-cylinder 4 of a countersinking hammer. The hammer drill head is provided with the hard metal cutting edges 5, which are arranged crosswise in the radial direction on the free front end. Between each two cutting edges 5 are the laterally open longitudinal channels 6 over the entire length free end, as can be seen in Fig. 1. In addition, they converge towards the longitudinal axis of the percussion drill head (see Fig. 2). During the production of the longitudinal channels 6, two separate bores 9, 9 'running at an acute angle to one another are first made in the Drill bit 1 are incorporated, which are then exposed, for example, by laterally milling out the longitudinal channel 6. In each longitudinal channel, a wedge-shaped gusset 8 protruding in the form of a cutting edge is formed, which separates the two former bores 9, 9 'from one another and produces a guiding effect for the scavenging air As a result of this design, the longitudinal channels 6 taper in a funnel-shaped manner 7 'and 7 "of the longitudinal channels 6 supplied exhaust air is bundled in the latter and introduced with an increased blowing effect into the end face sector 10 of the hammer drill head. The air flow directed towards the center of the drill head now whirls up the rock cuttings and carries them with it as it flows off. To allow the air laden with rock dust to flow out of the borehole, the percussion drill head 1 is also provided with groove-shaped recesses 11 in an offset angular position to the longitudinal channels 6, which run from the sections of the drill bit face between the end face sectors 10 in the longitudinal direction towards the preliminary cylinder 4. Subsequent to the recesses 11, the preliminary cylinder 4 has outlets 12 which distribute the air flow into the borehole. Patent claims: 1. Impact drill head for compressed air operated countersink hammers with in the area of the outer drill head recesses scavenging air channels formed for supplying the exhaust air from the end-face bores of the preliminary cylinder to the bottom of the borehole, thereby characterized in that the laterally open over the entire length of the recesses, in the The base of the recesses incorporated scavenging air ducts (6) on their cutting edge side The mouth tapers in the shape of a funnel and converges towards the longitudinal axis of the percussion drill head are. 2. Impact drill head for countersink hammers, characterized in that each longitudinal channel (6) of two at an acute angle to each other, the air inlet side through one blade-shaped protruding, wedge-shaped gusset (8) separate bores (9, 9 ^ is formed. Considered publications:
German Auslegeschrift No. 1 021 399,
217 903;
German utility model No. 1 912 913. 1 sheet of drawings 709 690/4 11.67 Bundesdruclcerel Berlin