FR2519064A1 - BUTTON IN HARD MATERIAL FOR PERFORATION TOOL AND TOOL COMPRISING SUCH A BUTTON - Google Patents

Abstract

1. Stud made of hard material for a drilling tool, consisting of a head (6) prolonged by a body (7) intended to be set into the end of the tool in a chamber (4) having dimensions slightly less than those of the body (7), in which stud the outer surface of the body (7) has teeth (8) intended to penetrate the inner wall of the chamber (4) when the stud (5) is set into the chamber (4), characterised in that the teeth (8) are arranged along helices marked on the surface of the body (7).

Description

The present invention is in the field of drilling More

  particularly, it concerns drilling tools, for example tailings

  lants for pneumatic hammers, perforators or tricones.

  In drilling tools known until now, the surface of the tool that works is generally provided with extremely hard buttons (or pins) intended to penetrate into the ground like so many hardness points. FIG. classic consisting of a head

for example

  1 extended by a shank 2 intended to be placed at the end of the elongated tubes of a pneumatic hammer down-hole The working surface 3 of

  the head is pierced with cells 4 in which are crimped buttons 5.

  In Figure 1, a portion of the head 1 has been shown in section to show the structure of the cell 4 and the button 5 When the drill bit is in operation, the hammer hits the tail 2 of the cutter and this percussion is transmitted to each button 5, causing the burst

  rock by exceeding the resistance of the latter to compression.

  The buttons 5 are made of very hard material, for example tungsten carbide, stellite, boron carbide, amide, etc. The shape of the cell 4 is generally cylindrical and the button

  corresponding is also but this one has a slightly larger diameter.

  with the cell 4 The inner wall of cell 4 and the over-

  the outer surface of button 5 are carefully ground for crimping

  button 5 in the socket 4 The button can be put in place using a hydraulic press or a pneumatic hammer with or without

  temperature difference of the two elements to be crimped.

  Although perforation tools with buttons, such as

  above, perform a very efficient drilling work, they present

  However, there are some disadvantages In particular, it happens that after a certain period of operation the button is no longer secured to the cell in which it was crimped and begins to rotate on itself,

  in its alveolus, thus becoming much less effective.

  Moreover, when the button begins to turn on itself in its cell, it risks being extracted by the forces of inertia which

  urge the button when the punch tool is turned

  tion or by shocks produced by the hammer.

  In summary, it can be written that the disadvantages of known drilling tools reside mainly in the fact that the buttons may become detached from the cell in which they are housed. This problem is serious for all the buttons crimped on the surface. of the tool that

  works but it is even more serious for buttons placed on the

  of the tool as these are subjected to friction on the wall of the drilled hole. The present invention attempts to remedy these drawbacks It aims a button capable of being crimped into a cell very safely,

  that is to say without risk of disconnection of the button and its socket.

  The invention also relates to a perforation tool provided with buttons according to

  the invention, that is to say a very reliable tool.

  More particularly, the invention applies to a button in

  hard material for perforation tool, consisting of a head for the actual drilling work, extended by a body, preferably cylindrical,

  intended to be crimped at the end of the tool, in a dimple

  slightly lower than those of the body.

  According to the invention, the outer surface of the body comprises

  protruding parts intended to penetrate the inner wall of the

  ole when crimping the button in the cell.

  In a preferred embodiment of the invention, the projecting parts consist of teeth located along generatrices of the surface of the body. Preferably, the teeth are of triangular section.

  and it is advantageous to make each tooth with an angle at the

  about 900 However, the teeth can also be of

polder or semicircular.

  In a first embodiment of the invention, the height of each tooth is constant over the entire length of the tooth, whereas in

  a second embodiment, which will be preferred in the first embodiment, the

  each tooth is not constant, but it decreases linearly

  maximum height, at the end of the tooth located towards the head of the

  tone, up to zero height at the other end of the button.

  In order to better understand the invention, two embodiments of the invention will be described in greater detail, given solely for the purpose of

  Sample; and represented by the accompanying drawings.

  FIG. 1 represents an overall diagram of a perforation tool

  This figure shows how these buttons are arranged on the tool The buttons shown in this figure are smooth buttons, part of the state of the art known but it is of course possible to mount on the tool of Figure 1 buttons

according to the invention.

  Figure 2 shows, on a scale larger than that of the

  1, a first embodiment of a button according to the invention, with it the cell in which / is intended to be crimped. In this first mode, the teeth protruding from the outer surface of the body have a constant height. FIG. 3 shows a second embodiment of a button according to the invention, with the cell that corresponds to it. In this second embodiment, the protruding teeth do not have a constant height and they give

  thus to the body of the button a conical shape.

  FIG. 4 represents a section IV-IV of the button of the FIG.

  Figure 2 It also shows a section IV-IV of the button of Figure 3, made at the end of the body of the button where the height of the teeth is maximum Indeed, at this level, the section through a plane perpendicular to

  the axis of the button is similar to a section of the knob of Figure 2.

  Figure 5 shows a section V-V of the button of the figur

  3, performed at a level where the height of the tooth is almost zero,

  say near the end of the body of the button farthest from the head of

drilling.

  Figures 2 and 3 both represent buttons

  with a head 6 for the actual drilling work, extended by a cylindrical body 7 to be crimped at the end of a tool such as the tool of Figure 1, in a cylindrical cavity 4 The outer surface of the body 7 has teeth 8 intended to penetrate into the inner wall

  of the cell 4 during the crimping of the button in the cell.

  Referring first to Figures 2 and 4 which show a button in which the teeth 8 have a constant height over their entire length Thus the section through a plane perpendicular to the axis of the button is

  always identical to FIG. 4 The body 7 of the button has a diameter of

  their D at both ends and at the bottom of the teeth In order to crimp the

  button in the cell 4 of diameter Dl was of course provided a D-value D

  In FIG. 4, it is shown that the value of FIG.

  a circle of diameter D ', to be able to compare this diameter with the diameter

  Button Meter D teeth 8 all have an apex angle of about 900.

  The diameter on top of the teeth 8 has been marked in the figures by DM "The DM value" is of course greater than D and therefore D 'When crimping the button in the cell 4, the initial tightening between the button and the 'cell due to the difference in diameter D D', is therefore added the total

  teeth 8 in the wall of the cell 4.

  Referring now to Figures 3, 4 and 5, these figures show

  a button in which the teeth have a height that decreases linearly

  The diameter D of the body 7 of the button at both ends and at the bottom of the teeth is the same as that of the button of FIG. 2. The angle at the apex of the teeth 8 is still about 900 but the height of the tooth decreases linearly from a maximum height to

  end of the tooth located towards the head of the button (see Figure 4)

  at a height zero at the other end of the button In Figure 5, this height is almost zero We have spotted the diameter on top of the teeth by

  DM '' in FIG. 4, where this diameter is maximal. In FIG. 5, this dia-

  meter being almost zero, has been identified by D "m, the value D" m being practically

  The knob of FIG. 3 is actually anchored in the cell 4 during crimping. Indeed, in addition to the initial tightening of a value DD ', the penetration is added. total of teeth 8 in the cell The shape of the teeth allows more mounting

easy button in the cell.

  The button according to the invention has great advantages: Once crimped, the button is impossible to turn on

himself, in his alveolus.

  On the other hand, the presence of protruding teeth on the outer surface

  the body of the button increases the con-

  tact between the knob and the inner wall of the cell.

  Sequence a significant reduction in the effects of inertia related to the mass of the button The risks of extraction of the button out of its socket are therefore non-existent. The realization of a button according to the invention is not much more difficult than achieving a smooth button The teeth can be

  obtained during sintering or by any other method.

  Of course, the invention is not limited to the modes of

  which are just described as examples, but it also covers all the other embodiments which differ only in details, in alternative embodiments or in the use of

equivalent means.

  Thus one could consider replacing the straight teeth that have been described by helical teeth, that is to say that the teeth would not be located along the generatrices of the surface of the body, but

  along propellers drawn on this surface.

  One could also imagine teeth whose section is not triangular but trapezoidal or semi-circular or whose sides would for example involute circle. The invention could obviously apply to buttons whose outer surface of the body is not cylindrical, but for example conical, the structure and arrangement of the teeth being similar to those

  described above, for example in the description of FIG.

Claims (10)

  1. Hard material button, for perforation tool, consisting of a head (6) extended by a body (7) to be crimped at the end of the tool, in a cell (41 slightly smaller dimensions to those of the body (7), characterized in that the outer surface of the body (7) contains   projecting parts (8) intended to penetrate into the inner wall of the   vola (4) when crimping the button (5) in the cell (4).   2. hard material button according to claim 1, characterized in that said projecting parts (8) are constituted   by teeth (8) located along generatrices of the surface of the body (7).   3. hard material button according to claim 1, characterized in that said projections (8) are constituted by teeth (8) located along propellers drawn on the surface of the body (7).   4. Button made of hard material according to one of claims 2 or 3,   characterized in that said teeth (8) are of triangular section.   5. Button made of hard material according to claim 4,   characterized in that the apex angle of each tooth (8) is approximately 90 o.   6. hard material button according to one of claims 2 or 3,   characterized in that said teeth (8) are of trapezoidal section.   7. hard material button according to one of claims 2 or 3,   characterized in that said teeth (8) are of semicircular section.   8 hard material button according to one of claims 2 to 7,   characterized in that the height of each tooth (8) is constant   along the entire length of the tooth (8).   Hard material knob according to one of Claims 2 to 7,   characterized by the fact that the height of each tooth (8) is not constant, but decreases linearly by a maximum height, at the end of the tooth   (8) located towards the head (6) of the button (5), up to a height of zero end of the button (5).   10. Puncture tool having a button (5) according to any one   conque of the preceding claims.