FR2523016A1 - FOREST GRINDER - Google Patents

Abstract

THE INVENTION CONCERNS A GRINDING MACHINE FOR DRILLS, ON WHICH THE DRILL 18 TO BE SHARPENED, MOUNTED IN A CHUCK 16 OF A TIGHTENING HEAD 14, CAN BE GRINDED ON THE CONICAL SIDES OR THE FOUR SIDES AGAINST THE FLAT SURFACE 48 OF THE GRINDER 26 A CRANK HANDLE 70 IS USED AS A DRIVING ELEMENT FOR THE EXECUTION OF THE DIFFERENT MOVEMENTS REQUIRED, IN PARTICULAR FOR CONICAL GRINDING. FOR TAPERED GRINDING, FLAT SURFACE 48 OF WHEEL 26 IS HELD IN ONE POSITION. WHEN THE POINT OF THE DRILL 18 IS TO BE SUBJECTED TO A FOUR-SIDED GRINDING, THE GRINDING OF THE EXTRACTED SIDES AND THE FREE SIDES REQUIRES TWO DIFFERENT ANGULAR POSITIONS BETWEEN THE DRILL 18 AND THE 26 GRINDING WHEEL. TO ROTATE AROUND AN AXIS B THE GRINDING WHEEL 26 AND ITS FLAT SURFACE 48. THE PIVOTING AXIS B IS LOCATED IN THE PLANE OF THE GRINDING SURFACE 48. SUCH AN ASSEMBLY ALLOWS AN EXACT GEOMETRY OF THE GRINDING TO BE OBTAINED ON FOUR SIDES, WITHOUT MODIFYING THE MOUNTING OF THE DRILL.

Description

Grinding machine for drill.

  The present invention relates to a drill grinder, comprising a grinding wheel with a flat grinding surface and a chuck which can pivot about a first axis, rotate about its axis, which is that of the drill bit.

  thresh, and move in the direction of this same axis towards the

  planar grinding face, the first axis being parallel to the

grinding face.

  A grinder of this kind can correct over-

  conical faces on the cutting edges of a drill, however, the conical grinding must often be replaced by a grinding of several surfaces on the point of the

  drill bits Known grinding machines of this kind allow

  usually either to correct the conical surfaces or

  to rectify flat surfaces Some machines can

  put however to obtain a conical grinding and a surface grinding But the disadvantage of such convertible grinders lies in the fact that it is necessary to use the lateral face of the grinding wheel to carry out the surface grinding The rectified surface is no longer flat , but hollow Now obtaining a hollow surface on the cutting edge of the drill gives an unfavorable cutting angle, which considerably reduces the life of the tool To obtain a perfect surface grinding, it is therefore necessary to use the flat surface grinding, i.e. the face

front of the wheel.

  The rectification of several surfaces being practically

  the only one made on drills of relative diameters-

  important to be able to take pi-

  vote the mandrel in relation to the grinding wheel, in order to rec-

  tify in a first position the two sides in

  bit of a double-edged drill, and the two faces li-

  bres in the other position Between these two operations, there

  you must therefore change the angle of the mandrel relative to the piece

  the However, to avoid the waste of time entailed

  by readjusting the mandrel or reassembling the drill, the a-

  xe corresponding to the aforementioned relative pivoting must be

  kill in the plane of the grinding face.

  A grinder of this type meeting the men-

  known, for example, from DE-OS 30 28 960.

  On this grinding machine, the mandrel is supported by an angle arm which pivots around an axis located in the plane of the grinding surface. This machine is not, however, fitted with an expensive displacement system allowing

  rectify the conical faces It is also

  tine drills of small diameter, 6 mm maximum for example For the above reasons, the mandrel provided on this type of grinding machine is relatively light, so that its mounting on the swivel arm is of no consequence for

stability.

  If the machine is also to be used for rectifying over-

  conical faces, its chuck must be fitted with the

  Adequate displacement heads If this machine is to

  be able to grind larger drill bits, of di-

  meters up to 30 mm, for example, the weight

  maple of the corresponding mandrel and the parts connected to it no longer allows the latter to be mounted on the swivel arm, as described in DE-OS 30 28 960, without laying

some stability issues.

  The grinding machine known from CH-PS 330 589, for example, can

  puts to grind conical surfaces If this machine

  also allows rectification on four fa-

  These rectifications are only possible with the information

  above mentioned The exact geometry of the rec-

therefore not guaranteed.

  On the grinding machine known from US-PS 2 724 931, the

  positive clamping provided for the drill is mounted on a carriage with two rectangular movements A crank,

  connected to a wheel meshing in a rack, per-

  puts to move this carriage parallel to the surface of

  grinding If such a drive ensures a downward movement

  back and forth from the drill along the grinding wheel, it does not lend itself to the precise adjustment that the rectification of

  certain drills or certain surfaces on the side

  rale of the grinding wheel The grinding on the lateral face

  can be important for sharpening taps, for example.

  The present invention aims to create a grinding machine for

  ret perfectly adapted to a rectification of the co-

  nics and a rectification on four faces of drills

  Helical grinding on four sides does not require

  te only one assembly of the drill, without further adjustment.

  This grinding machine also allows pre-positioning

  drill bit along the grinding surface and a

  Controlled back-and-forth movement in front of the grinding wheel

  back and forth allows in particular to obtain a recti-

  fication on four sides, the drill being directed from

  contour of the grinding wheel on the flat grinding surface.

  According to an essential characteristic of the invention, the grinding surface parallel to the first pivot axis corresponds to an initial position of the grinding wheel, from which the latter pivots about a second axis

  perpendicular to the first, located in the plane of the sur-

  Grinding face cut by the axis of the mandrel Another essential characteristic of the present invention is

given in claim 12.

  With the solution corresponding to claim 1, the

  grinding machine in accordance with the present invention makes it possible to

  achieve, with a single assembly of the drill, a correction

  conical or on four sides For the latter type of rec-

  tification, the geometry resulting from the mounting of the grinding wheel makes it possible to pivot only the latter between the operations of rectification of the undercut faces and of the free faces It is therefore unnecessary to move the mandrel and the drill mounted in the latter This mounting therefore ensures a exact geometry of the tip of the drill, as well as a

  perfect symmetry of its two cutting edges.

  Another specific solution of the invention is given

  in claim 12 This solution is specific-

  advantageous for grinding on four sides, each reciprocating movement, than the pivoting lever

  gives the cross carriage and the mandrel mounted on it

  deny, allowing to rectify each of the four faces.

  The preferred stroke of the carriage may be equal to 50 mm.

  With this movement of the carriage via the

  turn swivel, it is easier for the operator to de-

  terminate the feed during operation using the

  resistance produced Compared to screw drive-

  mother for example, such a mounting allows better

  determination of the adequate advance speed L'entra; -

  In addition, the lead screw is useful when it is essential to position the drill exactly on the X axis; this is the case, for example, with the sharpening of taps around the edge of the grinding wheel. A neutral position between the two mentioned possibilities allows rapid manual movement of the carriage with rectangular movements, which can

  then be driven either by the mother screw or by the

swivel lever.

  For a grinding machine intended for surface grinding only, for example, the corresponding construction form

  in claim 12 may be considered as an in-

  vention independent In this case, the mandrel mounted on A) the cross carriage must naturally not present the

  Characteristics of claim 1, or its preamble-

at least bule.

  Other advantageous embodiments of the present invention

  are given in the other claims.

  An example of construction of the objects of the invention is illustrated in the appended drawings, which represent: Figure 1: a top view of a drill grinder, Figure 2: Figure 3: Figure 4: Figure 5:

  the three movements of a drill for the-recti-

  fication of conical surfaces, a front view of the grinding machine shown in FIG. 1, without the clamping head, a crank mechanism making it possible to pivot the clamping head,

  a top view of the elements ensuring the movement

  cementation of the cross carriage on the X axis, Figure 6: a side view of the elements shown on the

figure 5.

  The drill grinder shown in Figure 1 has a base 10, on which is mounted a cross carriage 12 A pivoting clamping head 14 is mounted on the same carriage 12 This head 14 has a mandrel for

  clamp 16, in which is mounted the sharpening drill 18.

  To ensure exact centering of slope drills and

  large diameter, the chuck 16 is pre-

  references a six-jaw chuck The base supports two vertical uprights 20 and 22, on which a support 24

  can pivot about a horizontal axis B A large piece of furniture

  the 26 and a small grinding wheel 28 are mounted on this same

support 24.

  The base 10 supports a first slide 30, on the

  which a maneuver of a flywheel 32 makes it possible to move a second slide 34 on a Y axis On this same slide 34, the cross carriage 12 can be moved on the X axis by means of a second flywheel 36 , provided that the two-position lever 38, mounted on the second slide 34 opposite the flywheel 36, is in position I.

  When the lever 38 is in position II, the lever pi-

  Voting 40 allows the carriage 12 to move back and forth on the X axis When the lever 38 is in the initial position located between the two positions I and II, the cross carriage 12 can be moved by hand over the X axis.

  While the steering wheel 36 provided with a graduation 42 is pre-

  seen for precise adjustment, the lever 40 is intended to

  facilitate the movement back and forth of the carriage 12, when

  that for example a rectification of over-

  face on the point of the drill 18 The initial position of the lever 38 allows to quickly bring the cross carriage

  12 in another position, in front of the grinding wheel 28 for example

  ple Like the steering wheel 36, the steering wheel 32 has a

  duation 44 These two graduations 42 and 44 make it possible, on the one hand, to obtain a precise and controlled movement, and to reproduce, on the other hand, certain positions In order to guarantee this reproducibility, the operation of the lever 38 in the positions I or It is only possible for certain positions of the carriage 12 along the axis X. The large grinding wheel 26, driven by a first motor 46, has a flat front face 48 The small grinding wheel 28, driven by a second motor 50, is rounded on its

  outer edge, and tapered inside and out.

  The flat surface 48 of the large grinding wheel 26 must be situated exactly on the pivot axis B To fulfill this condition, the grinding wheel 26 can be moved along its axis D by means of a flywheel 52 The flywheel 54, provided near the small grinding wheel 28, adjusts

in height this same wheel 28.

  Another handwheel 56 makes it possible to pivot the support 24 around the axis B The graduation 58 makes it possible to obtain an approximate reading of the pivoting angle Another

  graduation 60, provided on the steering wheel 56, allows adjustment

very precise ge from this same angle.

  In order to be able to carry out a conical grinding on the point of the drill 18 during its sharpening, the mounting of the clamping head 14 allows the parallel execution of three movements. These three movements are represented by

  arrows in figure 2 The letter C designates the axis of the

  ret, which coincides with the axis of the mandrel 16 and will be called

  below the axis of the mandrel The arrow 62 illustrates the pre-

  mier movement, during which the drill 18 pivots around

  from a point 64 located on a first vertical axis A.

  The distance between the first axis A and the second axis B ho-

  rizontal, already mentioned, is a function of the diameter of the

  ret 18 to sharpen To respect the required distance between these two axes A and B, it is essential to mount the

  drill bit 18 in the mandrel 16 with the corresponding length.

  The second movement to obtain co-

  nics corresponds to the rotation of the drill 18 around its

  axis C, movement illustrated by circular arrow 66.

  The third movement is the advance movement of the fo-

  ret 18 towards the grinding wheel 26 along the axis of the mandrel C.

  For a two-edged drill, two movements of approach

  che must correspond to a rotation Each movement

  approach is followed by a backward movement This movement

  ment is illustrated by the double arrow 68.

  The mounting of the mandrel 16 in the clamping head 14 allows

  puts the simultaneous execution of the movements illustrated in Figure 2, when the crank handle 70, serving as a drive element, is rotated The clamping head 14 has an intermediate plate 72 pivoting around the first axis A on the carriage cross 12 and retained on

  this same carriage 12 using a stop screw 74 An-

  tip of the sharpening drill bit can be read on a gradation 76 The cross carriage 12 has a curved guide groove 78, provided for the intermediate plate 72 The clamping head 14 performs relative to the plate 72 the movement of pivoting 62 (Figure 2) The mandrel 16 performs the approach movement 68 (Figure 2) relative to

at the clamping head 14.

  A wheel 80, mounted laterally on the clamping head 14,

  allows to adjust a reduction gear provided between the poi-

  crank 70 and the mandrel 16, in order to be able to pass from two-edged drills to three-bit drills

  sharp edges, and even multi-edge drills

tually.

  A cam 82, connected to the crank handle 70 by the

  intermediate of the aforementioned gear, is contacted by a

  first transmission element 84 The cam 82 and the element

  ment 84, which is preferably a roller, constitute the first elements of a transmission system, which makes it possible to transform the rotational movement produced by

  the handle 70 in an axial movement 68 (Figure 2) The

  me 82 can be changed and / or reversed by loosening a knurled nut 86 The inversion allows sharpening drills cutting to the left You must then rotate the clamping head 14 on the right side of the carriage 12 by loosening

the stop screw 74.

  Another wheel 88, provided on the clamping head 14, allows

  set to adjust the stroke for the approach movement 68

  (figure 2) This stroke is adjustable from 0 to a maximum.

  The two levers 90 and 92, which each have a poi-

  ball-jointed, used to lock the mandrel 16 in predefined angular positions The right lever 90 is intended for drills cutting on the right, the left lever

  92, with the drills cutting to the left In position I, the handle

  drin 16 is locked in the initial position intended for clamping and centering the drill 18 In position II, the lock is ensured to thin the drill 18 on the small

  grinding wheel 28 Position O corresponds to the loosening.

  The vertical axis A already mentioned corresponds to the center of the scale 76 and of the guide groove 78 The axis of the mandrel C, horizontal, cuts at right angles the first axis A The second pivot axis B is perpendicular to the first axis A , but does not cut the axis D of the large grinding wheel 26 cuts the axis B at right angles When the support 24, and therefore the grinding wheel 26, are in the initial position, the

  flat grinding surface 48 of the same grinding wheel 26 is not

  parallel to the first pivot axis A. According to the invention, the second axis B is located in the plane of the grinding surface 48 and cuts the axis-of the mandrel C, so as to be able to pass from a conical grinding to a grinding of surface, rectification of the four faces of a drill with two cutting edges for example, without dismantling the drill To allow a thinning of the drill on

  small grinding wheel 28 with the same mounting, the lower edge

  laughing of this same grinding wheel 28 is located near the

  cond pivot axis B. Figure 3 shows a front view of the grinding machine shown in Figure 1, the clamping head 14 and the intermediate plate 72 having been removed for clarity A comparison between Figures 1 and 3 shows that the intermediate plate 72 and the head of

  clamp 14 are mounted on the cross carriage 12, re-

  presented in Figure 3 In addition, Figure 3 per-

  puts to see that the big wheel 26 is surrounded by a-

  protective sheet 94 in two parts, which extends

  tily, with an intermediate free space, beyond

  the flat grinding surface 48 The small grinding wheel 28 is

  partially enveloped by a protective sheet 96 As

  previously described, the steering wheel 54 makes it possible to adjust in height

  the small wheel 28 The latter, used for amin-

  cissage of the drill, is generally adjusted to a height such that its lower edge is located near the axis

  B Immediately to the right of the large wheel 26, a hollow

  ment 98 in support 24 facilitates access to the side face of this grinding wheel The side face of the large

  grinding wheel 26 is for example used to sharpen taps.

  The steering wheel 56 allows, preferably by means of a

  gear by cogwheel and rack, housed in the

  both 20 and not shown, to pivot the support 24 with the two grinding wheels 26 and 28 around the second axis B. FIG. 3 shows that the assembly conforms to

  the invention of the large grinding wheel 26 corresponds to a cons-

  truction of great stability To obtain a rec-

  perfect specification, such an assembly must be largely free of vibrations This condition is obtained by

  shape of bridge given to support 24.

  FIG. 4 represents a crank mechanism, housed in

  the clamping head 14 and connecting the latter to the plate

  that intermediate 72 (FIG. 1) This mechanism makes it possible to pivot the head 14 relative to the plate 72 in the direction of the arrow 62 (FIG. 2), when the handle

  crank 70 serving as drive is turned This pivo-

  This takes place around the first axis A, adjacent to the

tip of the drill to be sharpened.

  This mechanism comprises a connecting rod 200, articulated between a crank 202 and a splint 204 The end of the splint

  204 opposite the connecting rod 200 is fixed on the inter-plate

  medial 72 using a journal 208, around which

  it is articulated The splint 204 is however no longer ar-

  ticulated, when a conical stop bolt 206 is inserted

  in a bore of this same joint When, by the

2523016:

  gear train not shown, a maneuver of

  the handle 70 rotates the wheel 210 supporting the ma-

  level 202, the clamping head 14 pivots relative to the intermediate plate 72 in the direction of the arrow 62, the splice bar 204 being blocked The casing of the head 14

  is illustrated by the number 14 'in Figure 4.

  If a rotational movement must be carried out without the

  pivoting element represented by arrow 62, the stop bolt 206 is removed from the bore of the splint

  204 by means of a screw not shown The clamping head

  ge 14 is simultaneously blocked on the intermediate plate

  diary 72 by elements not shown When the crank wheel 210 performs a rotational movement, the splint 204 pivots around the pin 208 It is

in this case without effect.

  Such a mechanism has essentially two advantages, the first residing in the fact that the engagement / disengagement is only possible by means of a stop bolt,

  the second in the fact that the correspondence between the an-

  gle of rotation of wheel 210 and pi-

  vote in the direction of arrow 62 is restored after

each blocking by the bolt 206.

  Elements for moving the cross carriage 12

  on the second slide 34 along the X axis are re-

  shown in Figure 5 The operating elements re-

  presented in FIG. 1 are constituted by the flywheel 36,

  the two-position lever 38 and the pivoting lever 40.

  The other parts of this reversible displacement system are located inside the second slide 34 A first bar 220, movable in the longitudinal direction, is

  connected to the steering wheel 36 via a rod 238.

  A second bar 222, movable in the longitudinal direction and

  opposite the first bar 220, is connected to the lever pi-

  voting 40 Bars 220 and 222 have several evi-

  234 and 236 distributed lengthwise.

  An element 224, placed between these two bars, is provided

  to engage in recesses 234 A second element

  ment 226 is provided to engage in the recesses 236 of the second bar 222 These two elements 224 and 226 constitute the ends of a rack 232, which a toothed wheel 230 (see FIG. 6) allows to move in the direction of its length, that is to say transversely to the two bars 220 and 222 To train

  the cross carriage 12 in the direction of the X axis, the wheel den-

  tee 230 and rack 232 are connected to this same chain

  riot 12 via elements not shown.

  The toothed wheel 230 ensuring the drive has a central square hole crossed by a square bar 228,

  on which the wheel 230 moves in the axial direction.

  The square bar 228, which may have another profile, can turn on itself and is integral at one of its ends with the lever in two positions 38 When the lever 38 is in the neutral position, the rack 232

  is also in the rest position It is di-

* dimensioned so as not to engage in either of the two movable bars 220, 222, when it is in this initial position The cross carriage 12 can then be moved by hand along the X axis When the lever 38 is placed in one of its two positions, the element 224 engages in one of the recesses 234, provided that the carriage 12 has previously been brought by hand

  at the corresponding point The flywheel 36 then makes it possible to

  place this same carriage 12 precisely along the axis X. When the lever 38 is placed in the opposite position, the second element 226 engages in one of the recesses 236,

  provided that the carriage 12 has been previously moved

  hand-born in the corresponding position A maneuver-

  glass of the pivoting lever 40 then makes it possible to give the carriage

  12 a back and forth movement along the X axis The course

  what the carriage 12 can then do is for example

50 mm.

  The recesses 234 and 236 correspond at least to the positions in which the grinding operations must be carried out. These are for example the two grinding positions for drills cutting on the right and drills cutting on the left, of the two positions on the large grinding wheel 26, and at least one position

  on the small grinding wheel 28, used in particular for slimming

is lying,

Claims (13)

Claims.   1 drill grinder, comprising a grinding wheel (26) with   a flat grinding surface (48) and a clamping mandrel   ge (16) which can pivot around a first axis (A),   rotate around its axis (C), which is also that of the fo-   ret (18) to be sharpened, and advance in the direction of this same axis (C) towards the plane grinding surface (48), the first   pivot axis (A) being parallel to the furniture face   lage (48), characterized in that the grinding surface   (48) parallel to the first axis (A) corresponds to a posi-   initial tion of the grinding wheel (26), from which this   same grinding wheel (26) pivots around a second axis (B) per-   pendulum to the first (A), located in the plane of the sur-   grinding face (48) and cut by the axis of the mandrel (C).   2 drill grinding machine according to claim 1, characterized in that the axis of the mandrel (C) cuts at an angle   right the first pivot axis (A).   3 drill grinder according to one of claims 1   and 2, characterized in that the first pivot axis   (A) is vertical to a base (10).   4 Forest grinding machine according to any of the resales   dications 1 to 3, characterized in that the axis (D) of the   grinding wheel (26) cuts the second pivot axis (B).   Drill grinder according to one of Claims 3   and 4, characterized in that the grinding wheel (26) is mounted on a horizontal support (24), provided between two uprights (20, 22) connected to the base (10), uprights (20, 22) on which it is mounted and can pivot.   6 drill grinder according to claim 5,   characterized in that the support (24) can pivot at least   yen of a gear by cogwheel and rack-   linked to a drive element (56).   7 Drill grinder according to any of the   vendications 1 to 6, characterized in that the mandrel (16) is mounted on a clamping head (14) pivoting around the   first axis (A), this same head (14) having an e-   common drive element (70) for the three synchronized movements (62, 66, 68) (pivoting around the first axis (A), rotation around the axis of the mandrel (C)   and advances in the direction of the grinding surface (48)).   8 drill grinder according to claim 7,   characterized in that the clamping head (14) is mounted on a cross carriage (12), movable horizontally on   a base (10) along the X and Y axes, the X axis being   aligns with the flat grinding surface (48).   9 drill grinding machine according to claim 8, characterized in that the common drive element (70) for the three movements (62, 66, 68) is connected to a connecting rod (200) for the pivoting movement (62) , to a progressive adjustment gear for the movement of   rotation (66) and a cam (82) for the movement of   che (68), the axes of rotation of the driving element   ment (70), the crank (202) connected to the connecting rod (200), the wheels of the gear and the cam (82) being   parallel to the axis of the mandrel (C).   Drill grinder according to claim 9,   characterized in that the connection between the element of   drag (70) and the mandrel (16), via   of the connecting rod (200) and of the cam (82), can be interrupted stinks.   11 drill grinder according to one of claims 9   and 10, characterized in that an intermediate plate (72),   mounted between the cross carriage (12) and the clamp head   ge (14), can pivot around the first axis (A) and be   blocked on the carriage (12), in that the clamping head   ge (14) can also pivot around the first axis (A) relative to the intermediate plate (72) and in that   the connecting rod (200) mounted in the clamping head is articulated   abutment on a splint (204), which is itself hinged at its other end on the intermediate plate (72), on which it can be locked using a bolt conical (206).   12 Drill grinder according to any of the   vendications 8 to 11, characterized in that the cross carriage (12), movable on the slide (34) provided on the axis (A), can be engaged, either by a lead screw (36) for a precise movement, either by a pivoting lever   (40) for a back-and-forth movement.   13 drill grinder according to claim 12, characterized in that two bars (220, 222), movable in the longitudinal direction, are provided on the slide   (34), the first (220) being able to be moved by the   through the lead screw (36) and the second (222) via the pivoting lever (40), and in that the cross carriage (12) has gripping elements (224, 226) which can be engaged by means of a two-position lever (38) in the first bar (220) or in the second (222), or left free by means of this same lever (38).   14 drill grinding machine according to claim 13, characterized in that the two-position lever (38) is connected to a profiled bar (228), which extends in the longitudinal direction (X) and can rotate around itself, and on which is fixed a drive element (230), provided in the cross carriage (12) and movable lengthwise, this same element (230) being connected to the two grip elements (224, 226).   Drill grinding machine according to claim 14, characterized in that the drive element (230) has a toothing which engages in a rack (232)   connected to the plug elements (224, 226).   16 Drill grinder according to any of the resales   dications 13 to 15, characterized in that the bars   biles (220, 222) have several recesses (234, 236) distributed lengthwise, in which   the elements engage (224, 226).