Reverse Circulation DTH Button Bits

RC series reverse circulation DTH Hammer is the latest developed product of our company. It is mainly used for deep exploration drilling and ore grade control.
It has the following characteristics:
1. Based on previous experience of ordinary hammers, combined with the features of recerse circulation hammer, optimized internal structure and ideal energy transfer, thus ensuring the series of hammers deilling with fast smooth and continuous sampling.
2. The internal structure is very simple with components of high rigidity, thus ensuring long life and easy maintenance of the hammer.
3. The collection tube adopts an intergrative design and can be replaced without disassembling the hammer. With carburizing treatment, it has good abrasive resistance.
4. Equipped with bits designed with patent. Simply by replacing the drill bit, the same hammer can drill holes of different sizes ensuring that the sample is not contaminated.
 5. In difficult condition such as loose soil, hard rock and plenty of water exists, sampling can be done well.

Working principle
1. With the piston resting on the percussion bit and the hammer closed up in the drilling position, high pressure air is directed into the bottom chamber of the Hammer and the piston lifts. This commences the piston cycle.

2. As the piston travels upwards it forms the top chamber by forming a seal with the inner tube and the ID the piston. Further movement seals the port that feeds the bottom chamber and also simultaneously releases the seal on the bottom chamber allowing the air to expand and exhaust down the splines of the percussion bit. At the same time the Top chamber port is opened which feeds the high pressure air into the previously formed top chamber thus increasing the pressure above the piston and forcing it back down.

3.During the down cycle or power stroke the piston reseals the bottom chamber on the piston bearing bush thus stopping the exhaust air and creating a chamber of high pressure air below the piston which forces the piston back up the hammer.

4. Lifting the hammer of the bottom of the hole allows the percussion bit to slide down the drive sub also allowing the piston to slide down the hammer and rest on the piston bearing bush. The piston strike face and the strike face of the percussion bit can now not come into contact thus allowing the free flow of high pressure air directly through the hammer without the hammer cycling.
 

DTH Hammer Type		HRC45	HRC55	HRC65	HRC52	RC542	RC543	RC545	RC547
Length (less bit)	mm	1020	1111	1250	1208	1191	1191	1261	1270
Weight (excluding bit)	kg	94	66.5	110	70	57	62	65	71
External diameter	mm	99	126	146	126	109.5	116	117.5	124.5
Bit shank		HRC45	HRC55	HRC65	PR52	RE542	RE542	RE545	RE547
Hole range	mm	114-127	133-152	155-190	133-146	113-130	120-135	122-135	130-146
Connection thread		upon the thread of the drill tube				3.5"-4" remet 4" metzke		4"-4.5" remet 4"-4.5" metzke	4.5" remet 4.5" metzke
working pressure	Mpa	1.0-3.0	1.5-3.5	1.5-3.5	1.5-3.5	1.5-3.5	1.5-3.5	1.5-3.5	1.5-3.5
Impact rate at 1.7 Mpa	HZ	30	35	28	35	35	35	35	35
Recommended Rotation Speed	r/min	25-40	25-40	25-40	25-40	25-40	25-40	25-40	25-40
Air consumption (m3/min	1.0 Mpa	8	16	20	16	12	12	16	16
	1.8Mpa	12	22	26	22	18	18	22	22
	2.4Mpa	16	28	35	28	26	26	28	28

 

Drill Bit	Bit Dia. (mm)	No. Air Holes	Gauge Buttons	Front Buttons	Weight (kg)	Part No.
HRC	115	2	8x14	8x13	14	HRC45-115
	140	2	8x16	8x14	16.5	HRC55-140
	165	2	8x18	8x16	19.5	HRC65-165
MIC	133	2	8x16	8x14	17.5	MIC-133
	140	2	8x16	8x14	18	MIC-140
	146	2	8x18	8x14	20	MIC-146
PR5	133	2	8x16	8x14	12.5	PR5-133
	140	2	8x16	8x14	13	PR5-140
	146	2	8x18	8x14	13.5	PR5-146
PR4	115	2	8x16	8x13	14.4	PR4-115
	127	2	8x16	8x14	15	PR4-127
	133	2	8x16	8x14	15.5	PR4-133