FR2700131A3 - Eccentric disc sander with disc brake. - Google Patents

Abstract

a) Eccentric disc sander with disc brake. b) The actuating means (31, 33) are provided on the side opposite the sanding disc (6) of the eccentric disc sander, in particular next to the on / off switch (4) within the radius of action of at least one finger of the user's hand, when the latter is in the working position, in particular associated with the on / off switch (4).

Description

"Eccentric disc sander with disc brake"

  The invention relates to an eccentric disc sander whose housing is provided with a

  On / off controller, in which a shaft driven by a motor is rotatable with respect to an eccentric shaft integral in rotation with a sanding disk; this eccentric shaft drives the axis of the shaft by rotating eccentrically and rotationally; the movement of this axis is determined comminuously by means of rolling drive means

  and / or braking means, one of which is a hollow bearing wheel which is slidably disposed in the housing by means of actuating and guiding means and actuating means.

  Such an eccentric disc sander is already known from DE-A1 36 25 535. The rotation of the motor is converted into a working movement for the sanding disc by an anchor bearing carrying the endpiece. eccentric of a shaft The working motion consisting of the sum of a rotational movement and a circular movement of the sanding disk is obtained in the following manner. The two-bearing shaft carries at its free end an eccentric pivot 25 The eccentric pivot has an eccentricity with respect to the axis of the shaft It carries

  concentrically at its axis a hollow tree of eccentricity

  that is mounted in two rolling bearings The shaft of

  centric is secured in rotation with the sanding disc If the shaft then rotates, the eccentric pivot

  that also turns and makes a circular movement

  at the same time with the eccentric shaft and the

  sanding disc with the same eccentricity as above

  above it around the axis of the tree The disc of ponça-

  ge and the eccentric shaft rotate due to

  bearing between the eccentric pin and the eccentric shaft If a braking torque is applied at the sanding disc or shaft

  eccentric, which is bigger than the couple of

  obtained by the positional friction then, the sanding disc and the eccentric shaft

  a circular motion without rotation.

  The sanding disc should then rotate only when proportionally strong material removal can be envisaged Rotation is undesirable when the driven sanding disc does not touch the work; that is to say when the braking torque

  missing and that the rotation speed of the grounding disk

  may increase in an uncontrolled manner or when

  the eccentric disk sander must work

  siment as an oscillating sander with a performance

  minimum abrasion In this case, there is a risk of

  limited in the known disc eccentric sander by a friction brake located at

near the sanding disc.

  The brake is made in a simple way, but still requires an exact adjustment in order to ensure a regular wear The brake must be

  dust-tight, because otherwise losses of fu-

  additional costs could lead to a

  unnecessary heating and a reduction in

  of the eccentric disc sander or

  destruction of the brake.

  born from the sanding disk in a forced rotation due to the thrust of the hollow bearing wheel fixed in rotation inside the eccentric sander to

  disc by turning an eccentric adjustment shaft

only with the eccentric piece.

  In the eccentric disc sander con-

  1 O nue, the actuating means for adjusting the working level are close to the sanding disk but

  away from the handle To set the operating

  the user must look away from the work, laterally on the sander and find the actuating means to control it with one of the

  hands removed from the handle This is

  convenient, disturbs work and can easily lead to

  re to errors of use In addition, it is expected

  rotary knobs for adjusting the level of

  To turn these buttons, the user must use at the same time at least two fingers of his hand. The present invention aims to remedy

  to these disadvantages and to this end relates to a

  of the type defined above characterized in that the actuating means are provided on the opposite side

  to the sanding disc of the eccentric sander

  that, in particular beside the switch on / off within the radius of action of at least one finger of

  the hand of the user, when the user is in

  work situation, especially associated with the on / off switch.

  The eccentric disc sander according to the

  vention has the advantage that the mechanical friction brake can be controlled in a

  particularly precise by a control stroke

  regular, the maneuver is particularly comfortable and easy The level of work can be switched

  only with one finger of the user's hand

  while the sander is working without having to

  remove one hand from the handle and

guard of the work.

  According to other interesting features

  santes: the rolling drive means and / or the braking means and the guiding means

  are provided on the end of the opposite shaft to the disc

than sanding.

  the guide means constituted by

  minus one stud secured to the housing on which

  the hollow bearing wheel with at least one ramp, in particular outer, so as to slide axially when it is rotated and the actuating means for rotating the hollow wheel of

  bearing comprises at least one working adjustment shaft

pouring the housing.

  the hollow bearing wheel rotates on the ramps with a tilting stroke of 1800 of the actuating means and thus passes from a position of

  switching to the other by its axial sliding.

  the adjustment shaft is coupled to the wheel

  hollow bearing through a pinion.

  the hollow bearing wheel carries on its outer cylindrical surface an oblique toothing by

  relative to its axis, and with which meshes the pinion.

  the toothing (38) corresponds to a crémail-

  parallel to the ramps and curved especially in

this longitudinal direction.

  the tree consists of a hollow shaft or-

  green at both ends in which is arranged

  the eccentric shaft protruding from both sides

your.

  the ramps are arranged on one of the

  these front of the hollow wheel rolling.

  the adjustment shaft is surrounded by a dust-tight bushing and in particular a bellows. braking means is provided in the form of a disk slowing the movement of the disk which acts in one of the switching positions of the actuating means. Drawings.

  An exemplary embodiment of the present invention

  will be described in more detail with the aid of

  Thus, FIG. 1 is a sectional view of an exemplary embodiment of an eccentric disc sander. Figures 2 and 3 are sectional views

  diagrams of the work level adjustment mechanism

  the eccentric disc sander.

  Description of the exemplary embodiment

  The eccentric disc sander shown in Fig. 1 comprises a motor housing 2 provided with

  power cable and switching

  On the motor housing 2 is clamped an angular gearbox 5 which has an angular drive 7 cooperating with the sanding disc 6 The bevel gearbox consists of a small

  conical wheel 8 mounted on a non-referenced motor shaft

  this and transmits the motor movement to a large

conical wheel 9.

  The wheel 9 concentrically surrounds,

  in rotation, a shaft 11 rotating

  turn of an axis 10 formed in the form of a hollow shaft 11 The shaft It is arranged in the angular gearbox 5, in a bearing 12 remote from the disk

  and a bearing 13 on the disk side at its end

  lower, the shaft 11 carries a counter weight 14 to balance the unbalance from the eccentric movement

  Sanding disc The shaft 11 presents a

  step through, eccentric with respect to

  the axis of rotation 10 The drilling 15 concentric box-

  an eccentric shaft 16 having the longitudinal axis

  tudinal 17 This longitudinal axis is parallel to the axis of rotation 10 offset from an eccentricity "e" The tree

  eccentric 16 is mounted on its far side of the

  sanding in a housing 18 made in the form of a fixed bearing and is guided at its end located on the side of the sanding disc, in a bearing 19 made to admit the radial forces in the form of a needle bearing with a sealing sleeve not shown The eccentric shaft 16 carries at its lower end the sanding disk The eccentric shaft 16 carries on its side remote from the sanding disk 6 an elastic ring 21 housed in a groove 20 and on which coaxially, successively, a support ring 22, a lower flat spring 23, a front toothed wheel

  24, a washer 25 with a non-reciprocal front toothing

  fermented, another washer 26, a flat spring 27 prestressed, upper and finally, as a blocking,

a screwed nut 28.

  The nut 28 may for example be replaced by another elastic ring; the flat spring 23 can be replaced by a spiral spring

  pressure, the flat spring 27 can be removed.

  The front toothed wheel 24 and the counter

  washer 26 are arranged, fixed in rotation,

  axially, on the eccentric shaft 16

  delle 25 can rotate around the eccentric shaft in the manner of a lottery wheel It is supported by braking between the front gear 24 and the counter-washer 26 The front gear 24 can

  have a smaller number of teeth than the one of the ron-

ringlet 25.

  A hollow bearing wheel 29 carrying two

  axially spaced identical teeth is

  The two sets of teeth 30 are arranged so that their pitch circle is tangential to the toothing of the front toothed wheel which is not referenced and to the ring washer 25.

  axial distance between the two teeth 30 is less than

  a tooth length of the toothing 30 to the distance between the front toothed wheel 24 and the annular washer 25 Thus, only the front wheel

  24 or the ring washer 25 can rely axially

  The rolling hollow wheel 29 is limited in its axial sliding and is rotatably disposed in the angular gearbox 5, so that it can be placed on one of the teeth 30. alternatively out of engagement of the front toothed wheel or the ring washer An adjusting shaft 31 coupled with the hollow bearing wheel 29 serves as a setting means for axially moving the hollow bearing wheel 29 This shaft

  of adjustment carries an actuating part 32 tilting

  from the outside The adjustment shaft 31 goes from

  The adjusting shaft 31 is provided with a locking device and is sealed by a circular bore 33 in the wall of the angle gearbox 5, surrounded by a dust-tight bellows 34 attached to the bevel gearbox 5. not shown with which the tilting position of the actuating piece 32 can be locked relative to the

  angle gearbox 5 in the final positions

  The positioning shaft 31 carries a pinion 37 at its end associated with the hollow bearing wheel

  29, the pinion is engaged with a rack

  clinée performed flush in the cylindrical surface

  outer surface of the hollow bearing wheel 29 and

  born to the sanding disk 6 The adjustment axis 31

  is blocked in axial translation at its opposite end

  fitted to the angle gear box using a ring

blocking 39.

  On the side of the hollow bearing wheel 29 opposite the adjustment shaft 31 is a slot

  oblique with oblique surfaces 35 appear-

  in the section in which is engaged a stud 36 attached to the bevel gearbox Other surfaces of the stud are not shown The slope

  surfaces 35 corresponds to the slope of the rack

re 38.

  When switching on the motor of the wheel

  1, which is not shown in greater detail with the aid of an on / off switch, the conical zones 8, 9 rotate. The conical zone 9 rotates at the same time as the shaft 11 in the same way.

  that the counter weight 14 rotates about the rotational axis

  The shaft 11 drives the eccentric shaft 16

  and the sanding disc 6 via the pa-

  These rotate around the axis of rotation 10 with an eccentricity "e" and rotate about their axis 17 because

  friction in the bearings 18, 19.

  The spur gear 24, the annular disk

  nular 25 and counter-disk 26 follow the movement

  eccentric shaft 16 in which, in the position

  1, the front gear wheel 24 is out of engagement and the annular disc 25 is engaged

  with the hollow bearing wheel 29.

  If the hollow bearing wheel 29 is

  due to a rotation of the adjusting shaft 31, the hollow bearing wheel moves axially on the slope of the inclined surfaces 35, the rack 38 and the pinion 37 then meshing with the axial sliding.

  of the hollow bearing wheel 29 causes the modification

  1 O cation of the level of work between a job

  If the lower toothing of the two toothing is coupled with the front gear 24, then the front gear 24 rolls on the hollow bearing wheel 29 and thereby forces the sanding disc to a speed less rotation than

  of the shaft 11 which is less than the rotation speed

  the eccentric of the sanding disk and which is composed with the eccentric movement

  corresponds to the gross work with an im-

carrying matter.

  If the upper toothing 30 is coupled with the disk 25 then this can according to FIG.

  depending on the difference in the number of teeth, oscillate

  tically without rotation along the toothing 30

  In this case, the annular disc 25 brakes the exchanger shaft.

  The sanding disk 6 can therefore be adjusted with a more or less rapid rotation speed without risk of runaway following the pre-stress of the braking device.

  the nut 28 This setting corresponds to the working level

  end with a low material removal.

  Because of the pre-stress using the flat springs 23, 27, the above parts are based

  on each other with a predetermined axial force

  This leads to a predetermined friction of the surfaces facing each other moving relative to each other The friction is variable and can be adjusted individually depending on the choice of the customer. As the bearing friction increases in the bearing 18 when the sanding disc is pressed on

  the work and increases according to the exer-

  by the user, the sanding disc does not start

  this to turn only when in contact with the book.

  FIGS. 2 and 3 are a diagrammatic representation of an angular gearbox 50, which

  corresponds in principle to that of Figure 1.

  A hollow bearing wheel 52 is guided in sliding

  Axially and rotatably on the inner wall 51 of the housing 50 The hollow bearing wheel 52 is

  (as an inclined plane) on its outer circumference.

  re, a rack 53 oblique or curved in the di-

peripheral rection.

  A pinion 54 engages with the rack 53, this pinion is arranged fixed on a control shaft

  which is arranged in a sealed and free

  The hollow bearing wheel 52 is moved axially toward or away from the sanding disc 50 in a hole 56 of the bevel gearbox 50 and is rotatable through an actuating member 57.

  according to the tilting direction of the

  The pinion 54 is arranged with an inter-

  valle in relation to the circumference of the hollow wheel

  52, so that when traveling

  axial cement of the hollow bearing wheel 52 there

  has no annoying friction with pinion 54.

  When tilting the actuating part 57, the hollow bearing wheel 52 undergoes a precisely adjustable axial displacement and communicates with the hollow bearing wheel 52 by sliding the ramps 58, 59 on the pivots 60, 61, this thrust is necessary to change the work step The tilting angle of 180 of the actuating part 57 corresponds to the

  passage of the hollow bearing wheel 52 from a position

  Switching speed to the other for maximum travel

axial sliding.

  In Figure 2, the teeth are recognized

  62, 63 one of which is coupled with the braking means

  on the eccentric shaft and the other with rolling drive means

  ring 64 constitutes a means of sealing between the

  position 55 and drilling 56.

  Figure 3 which is a view at 9 Q O of the example

  FIG. 2 shows, with the help of a curved arrow 65, the possible directions of rotation of pinion 54 and thus the direction of tilting of

  the actuating piece 57; a straight arrow 66

  the possibility of axial sliding of the wheel

hollow bearing 52.

  In a non-representative embodiment

  a friction gear or an eccentric pin of a pinion and a rack can be installed to effect the axial sliding of the hollow wheel

rolling.

  In another example of embodiment not re-

  presented of the invention can be arranged a lever to

  the place of the pinion located at the end of the axis of po-

  this lever rests in the manner of a machine.

  level between the cams on the periphery of the hollow bearing wheel and switches a setting of the mode of use with this lever as is known for

drills and punches.

Claims (2)

Claims) Eccentric disc sander (1) whose housing is provided with an on / off switch (4), wherein a shaft driven by a motor (11) is rotatable relative to an eccentric shaft (16) integral with rotating a sanding disc (6); this eccentric shaft (16) drives the axle (10) of the shaft (11) by rotating eccentrically and in rotation; the movement of this axis is determined in a switchable manner by means of rolling drive means (24, 29) and / or braking means (25, 29), one of which is a hollow wheel of bearing (29) which is slidably arranged in the housing (2; 5) by actuating and guiding means (35, 36) and actuating means (31, 33) characterized in that the means (31, 33) are provided on the opposite side to the sanding disk (6) of the eccentric disk sander, in particular adjacent to the on / off switch (4) within the range of at least a finger of the hand of the user, when the latter is in the working position, in particular associated with the on / off switch (4).   2) eccentric disc sanding machine according to claim 1, characterized in that the rolling drive means (24, 29) and / or the braking means (25, 26) and the guiding means (35, 36) are provided on the end of the shaft (11) opposite to the sanding disc (6).   30) eccentric disc sanding machine according to claim 1 or 2, characterized in that the guide means (35, 36; 58, 59, 60, 61) consist of at least one pin secured to the housing (36; on which the hollow bearing wheel (29; 52) is supported with at least one ramp, in particular an outer ramp (35; 58; 59), so as to slide either axially when it is rotated and the actuating means   (31, 33; 55, 57) for turning the hollow wheel of   (29; 52) has at least one adjusting shaft (31; 55) extending through the housing (2,5; 50). Eccentric disc sanding machine according to Claim 3, characterized in that the hollow bearing wheel (29, 52) rotates on the ramps (35; 58, 59) in a tilting stroke of 180 of the actuating means (31, 33; 55, 57) and thus switches from one switching position to another by axial sliding. ) Eccentric disc sander according to the   claim 4, characterized in that the control shaft   glazing (31; 55) is coupled to the hollow wheel of   (29; 52) through a pinion (37 54). 6) Eccentric disc sander according to   Claims 1 to 5, characterized in that the wheel   hollow (29; 52) bears on its surface cy-   the outer sleeve (40) has a set of teeth (38;   than in relation to its axis, and with which the pinion (37; 54).   ) Eccentric disc sander according to the   Claim 6 or 7, characterized in that the denture   re (38) corresponds to a parallel rack (38;   leashes ramps (35; 58, 59) and curved including in this longitudinal direction.   8) Eccentric disc sander according to   one of the preceding claims, characterized in that   the shaft (11) consists of a hollow shaft or-   green at both ends in which is disposed the eccentric shaft (16) projecting from both sides. _, 90) Eccentric disc sander according to   one of claims 3 to 8, characterized in that   the ramps (35; 58,59) are arranged on one of the end faces of the hollow bearing wheel (29; 52). 10) Eccentric disc sander according to   one of the preceding claims, characterized in that   the adjusting shaft (31) is surrounded by a dust-proof sleeve (34) and in particular a bellow.   110) Eccentric disc sander according to   one of the preceding claims, characterized in that   at least one braking means (25) is formed in the form of a disk slowing the movement of the   disc (6) which acts in one of the   tation of the actuating means (31).