BACKGROUND ART There are known rods whose ends have multi coils threaded conic portions respectively male and female for interconnecting said rods. In order to interconnect or detach a rod from the interconnected rods and under way, these last ones must be tightened, for instance by means of a vice or a rotary, to prevent their rotation and vertical motion, and the upper rod must be rotated, for instance by a rotary in a sense or in the other one for a number of turns equal or proportional to the number of coils to engage or disengage; furthermore the rod to be interconnected or disconnected must be supported for instance through a winch rope.

The main drawback of said known rods consists in the complexity and duration of the operations needed for the connection and disconnection of said rods and in the complexity of the related drill machine.

Other drawback consists in the risks for the operators assigned to said operations.

A further drawback consists in that, in correspondence of the operation of the known rods, these last ones can turn in screwing direction only, with the exception of further constructive and operational complications, for instance the application of connection pins.

There are also known rods, usually of the type having a continuous coil, whose ends have hexagonal joints, respectively male and female fit for transmitting a torque, and respective seats, generally tangential, for a pin fit for transmitting axial forces between the rods.

The main drawback of these last known rods consists in that the insertion and the disengagement of the tangential pin require a lot of time and involve risks for the operators assigned to said operation.

A further main drawback consists in that generally the known rods with continuous coil and hexagonal clutch cannot have a total length greater than about 30 meters.

DISCLOSURE OF THE INVENTION The main object of the present invention is to propose a drill rod with automatic clutch having a fast interconnection and separation, which is safe for the operators and does not require complicated or lots of drill machine means for the interconnection and disconnection, and to propose simple and safe rod disconnection means.

Other object is to propose a rod having a safe interconnection for deep drilling also over a thousand of meters.

The above-mentioned objects are achieved in accord with the content of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS The characteristics of the present invention are underlined in the following with particular reference to the attach drawings, in which: figure 1 shows a side view of a drill rod object of the present invention, in which some parts have been removed for better underlining others; - figure 2 shows a bottom enlarged view of the figure 1 rod of in which some parts have been removed for better underlining others; - figure 3 shows a top enlarged view of the figure 1 rod; - figure 4 shows a longitudinal section partial view of two rods in a clutch condition; - figure 5 shows a longitudinal section partial view of the figure 4 rods in a clutch and block condition; - figures 6A and 6B show longitudinal section enlarged views of respective end portions of pipes of the figure 3 rod; - figure 7 shows a partial section view of a first variant of the figure 4 rods in a clutch condition; - figure 8 shows the figure 7 rods in a clutch and block condition; - figures 9 and 10 show respectively sections IX-IX and X-X of the rods of figures 7 and 8;

-figure 11 shows an enlarged partial view of figure 8; - figures 12 and 14 show a partial section view of corresponding variants of the rods of figure 5 in the clutch and block condition; - figures 13 and 15 show sections respectively according to plain XIII-XIII and XV-XV of figures 12 and 14; - figure 16 shows a side schematic view of disengagement means in a proximity condition to the upper end of a rod, in which some parts have been removed for better underlining others; - figure 17 shows a variant of the figure 16 rod; - figures 18 and 19 show respective operational conditions of a variant of the figure 16 disengagement means.

BEST MODE OF CARRYING OUT THE INVENTION With reference to the figures from 1 to 5, numeral 1 indicates the drill rod with automatic clutch object of the present invention.

The rod 1 has an inner longitudinal cavity 7 flowing in correspondence of the ends of said rod 1.

The ends of the rod 1 have respectively a male clutch 5 and a female clutch 3 having a shape almost complementary to the male clutch 5. The clutches, male 5 and female 3, are hollow and have cross section approximately shaped as regular polygon with chamfered vertexes, preferably a hexagon. The clutches male 5 and female 3 have respectively a couple seats, first 8 and second 21.

In an engagement condition P between two consecutive vertical rods, the first seats 8 of the upper rod face the seconds seats 21 of the lower rod.

The seats first 8 and second 21 are carried out, for instance, in correspondence of two opposed chamfered vertexes of the clutches male 5 and female 3 or in correspondence of the sides of these last ones.

The second seats 21 can be also carried out in correspondence of all the chamfered vertexes or all the sides to allow to get an engagement condition P between two rods, facing the couple of first seats 8 to a couple of second seats 21, independently from the mutual axial

position of the two engaged rods.

It is provided that both the first seats 8 and the second seats 21 can be carried out in correspondence of all the vertexes or all the sides of the clutches male 5 and female 3.

Respective stop means 9 are accommodated into the first seats 8, in a sliding way between two opposite positions, an inner one and an outwards protruding one of the male clutch 5, said stop means 9 substantially consisting of cylindrical pins having flat surfaces.

Locking means 50 slide in the cavity 7, between two opposite conditions, unlocking S and stop I ; said locking means 50 having transmission means 13 for translating the stop means 9 in the protruding position in correspondence of the passage of the locking means 50 from the unlocking condition S to the stop condition I and vice versa.

The locking means 50 also include a head 18 fixed to the transmission means 13 by means of a bar 17.

The transmission means 13 include, for each stop mean 9, a couple of parallel plates 14 having respective facing cam seats 12 consisting of shaped grooves.

The innermost end with respect to the rod 1 of each stop mean 9, that is each cylindrical pin, has in correspondence of the flat surfaces, a hole 10 for the median portion of a pivot 11.

The ends of the latter are constrained to slide in the cam seats 12 of the couple of parallel plates 14 related to the stop mean 9 connected to said pivot 11.

The cam seats 12 converge toward the rod 1 axis in opposite direction respecting the female clutch 3 or, in an operational condition, downward therefore the stop condition I of the locking means 50 is lower with respect to the unlocking condition S.

Each cam seat 12 has end portions 15, almost parallel to the axis of the rod 1 and filleted by an interposed slanted portion 16.

The side portion of each plate 14 slidably mates with slack a portion 32 of the hollow 7 for instance corresponding to a circular crown of the rod 1 protruding inside this latter. Said

sliding abutment avoids slaps of the lower end of the locking means 50.

In an engagement and blocking condition T, the male clutch 5 is inserted in the female clutch 3, each first seat 8 of the upper rod 1 faces a second seat 21 of the lower rod 1 and each stop mean 9 fills both its own first seat 8 and a second seat 21.

In the engagement and blocking condition T, the head 18 of the locking means 50 of the lower rod 1 mates the male clutch 5 of the other rod.

The head 18 has a plurality of flanges 19, preferably four, radially positioned, approximately at"X", and slidably mating the wall of the hollow 7 in order to avoid slaps of the upper end of the locking means 50.

Referring now also to the figure 16, the end of the head 18 opposed to the rod 17, that is the upper end of the head, has hooking means 20 for disengagement means 29. The hooking means 20 for instance consists of an oval opening or in a protruding body.

The disengagement means 29 include a connection for a lifting winch rope of the rod 1 and a couple of jaws 30 operated by a first jack 31.

Referring now also to figures 6A and 6B, the rod 1 may include a plurality of pipes 22, for instance two, fixed inside the hollow 7. An end of each pipe 22, has a mouthpiece 23 complementary to the other end 24 and having an annular seat 25 for sealing means 28 consisting of, for instance, a gasket 26 and eventually a possible an anti-extrusion ring 27.

The pipes 22 are fit, for instance, for the flow of a liquid removing the deposit dug through the inverse circulation method.

The rod 1 may also include a plurality of guides 38 longitudinally and externally fixed, preferably in correspondence of the second seats 21 for protecting a tapered portion of the external end of the stop means 9.

The guides 38 are provided for the slide of baskets for the removal of the excavation crumbled material and eventually for the excavation.

The operation provides that the connection between two rods 1 is carried out by holding, for

instance by means of a rotary or a vice, the lower rod 1 and positioning the other rod 1 vertically on the lower one, for instance using the disengagement means 29 engaged in the hooking means 20 and fixed to the lifting winch.

The stop means 9 of the upper rod 1 are in retracted position because the weight of the rod 1 loads on the locking means 50, which therefore assume the upper position corresponding to the unlocking condition S. This allows inserting the male clutch 5 of the upper rod in the female clutch 3 of the other rod.

If there are second seats 21 only on some vertexes or sides of the female clutch 3, said engagement must be done having care that the first seats 8 of the male clutch 5 of the upper rod 1 correspond to second seats 21 of the lower rod 1. At the contrary if there are second centers 21 on all the vertexes or sides of the female clutch 3, the mutual positioning of the two rods 1 is indifferent.

Because the loosening of the winch cable, the weight of the hooking means 20 or the action of other means, cause the translation of the locking means 50 downward up to the stop condition I causing the insertion of the stop means 9 of the upper rod into the second seats 21 of the lower rod, so obtaining the engagement and blocking condition T between two rods 1.

In said condition, the shape of the clutches male 5 and female 3 allows, in substance, to transmit torques, even very high between the rods 1, while the engagement of the stop means 9 of the upper rod in the second seats 21 of the other rod 1 allows to transmit longitudinal forces between said rods 1, reciprocally locking these last ones.

The contact of the head 18 with the male clutch 5 end of the upper rod prevents movements of locking means 50 assuring the maintenance of the engagement and blocking condition T of all the engaged rods.

The disengagement of an upper rod 1 is carried out by holding, for instance by means of a rotary or a vice, the adjacent lower rod 1 and positioning vertically over the rod 1 to be disengaged, the disengagement means 29, fixed to the lifting winch.

The disengagement means 29 are operated to engage the hooking means 20 and the

operation of the lifting winch causes the lifting of the locking means 50, which consequently rise with respect to the rod 1 to be disengaged, reaching the upper position, corresponding to the unlocking condition S, causing the disengagement of the stop means 9 from the second seats 21.

A further operation of the winch causes the lifting and the full disconnection of the upper rod 1.

In correspondence of the engagement and disengagement of two consecutive rods, the ends of the possible pipes 22, can be inserted because the axial movements between the two rods 1.

In the variant of figures from 7 to 11, the transmission means 13 have a truncated conical portion 33 with vertex turned outwards the respective rod 1 and fit to match stop means 9 consisting of spherical bodies held in the respective first seats 8 by holding means 34, consisting of elastic rings housed in annular housings carried out in proximity of the external outlets of the first seats 8.

In correspondence of the engagement and blocking condition T, the truncated conical portion 33 translates radially outward the spherical bodies, whose a cover portion engages an annular shaped second seat 21 with circumference portion concave profile.

In correspondence of the unlocking condition S of the locking means 50, the spherical stop means 9 are free to translate between the holding means 34 and the truncated conical portion 33 allowing the disengagement between two consecutive rods 1.

In this variant there are provided gasket means 36, for instance consisting of O-Ring or other sealing means with related seats and abutments, associates to the female clutch 3 and to an outlet of the locking means 50 which are tubular.

In the engagement and blocking condition T, the gasket means 36 carried out the watertight between locking means 50 of consecutive rods 1 and between said rods realizing two canalizations, one inside the locking means 50 and one consisting of in the hollow space between these last ones and the walls of the rods 1. Said canalizations have the same functions of the pipes 22, being fit for the inverse circulation or for the hydraulic feeding of

tools fixed to the rods I.

The end of the locking means 50, opposed to the transmission means 13, has centering means 37 consisting for instance of three or four radial fins sliding against an inner protuberance of the rod 1 and provided with a related abutment 39 fit to match the inner protuberance in order to prevent the exit of the rod locking means 50, in direction of the female clutch 3, so defining the unlocking condition S.

The truncated conical portion 33 has a respective abutment 40 fit to match the stop means 9 to prevent the exit of the rod locking means 50 in direction of the male clutch 5, so defining the stop condition I.

The operation of this variant does not differ substantially from that previously described.

The variant of figures 12 and 13 differs from that one of figures from 7 to 11 in that there are provided two annular second seats 21 spaced apart positioned on two plans transversal to the rod.

A set of six first seats 8 corresponds to each second seat 21 and a respective truncated conical portion 33 of the transmission means 13 corresponds to each set of said first seats 8.

The operation of this variant does not differ substantially from that one previously described, but it allows an increase of the axial forces transmitted between the rods 1.

In the variant of figures 14 and 15, the clutches male 5 and female 3 have a cylindrical shape and each second seat 21 is shaped as hollow spherical cover and is carried out in an insert 35 welded to the female clutch 3.

The operation of this variant does not differ substantially from that one previously described, with the exception that the stop means 9 transmit axial and also rotatory forces between the rods 1.

The variant of the figures from 17 to 19 refers to disengagement means 29 including a tubular body 49 fit for containing at least a portion of the female clutch 3, provided with two diametrical related cavity 52, a rod 1 to be locked or unlocked from another rod 1.

The tubular body 49 is internally provided with a second jack 51 for the axial translation of a support element to which the jaw 30 is hinged and the first jack 31 is fixed, the latter moving near or away the jaw 30 from a fixed catch of the support element. The tubular body 49 supports, by means of two inner pivots 54, two arms 43 symmetrically moved, through respective slots of the body 49, by a couple of parallel third jacks 48, between two opposite positions, one inner of maximum mutual approach and one partially external of maximum divarication.

Each arm is provided with a protuberance 44 fit to engage the related cavity 52 and a shoulder 45 fit to mate the external edge 53 of the rod 1 near the cavities 52. The tubular body 49 further includes a plurality of tapered portions 42 internally fixed to the mouthpiece of the body 49 and fit to make easier the insertion of the female clutch 3 into the body 49.

The operation of this variant provides that the female clutch 3 is inserted in the disengagement means 29 in a condition of maximum divarication of the arms 43 and of maximum distance between the jaw 30 and the relative fixed catch.

The operation of the third jacks 48 causes the insertion of the protuberances 44 into the related cavities 52 and the mating of the shoulders 45 with the edge 53 obtaining a rigid fixing of the disengagement means 29 to the rod 1.

The driving of the second jack 51 causes the coupling of the jaw mean 30 to the hooking means 20 of the rod. The driving of the first jack 31 causes the passage of the locking means 50 from the stop condition I to the unlocking condition S or vice versa, leading the consecutive two rods 1 in an engagement and blocking condition T or an engagement condition P without the aid of vices, winches or other means. Obviously the disengagement means 29 can be fixed to the cable of a winch for the rod 1 movement.

The main advantage of the present invention is to provide drill rods with automatic clutch and disengagement means, having fast engagement and disengagement, which are safe for the operators and do not require complex or numerous means of the drill machine.

Other advantage is also to provide rods with a safe interconnection for deep drilling even over a thousand of meters.