FR2480662A1 - VERSATILE MACHINE FOR ANGLE SANDING - Google Patents

Abstract

THE INVENTION CONCERNS A MACHINE ALLOWING TO REALIZE WITH A SINGLE TOOL THE SANDING OF CONVEX ROUNDING IN QUARTER ROUND WHATEVER THEIR RADIUS BY USING THE ENTIRE WIDTH OF STANDARD ABRASIVE STRIPS, WHICH SANDING TYPE IS OF THE SANDING TYPE. SIMILAR TO MANUAL LONG SANDING, THE ATTACK OF THE ABRASIVE BAND TANGENTIALLY TAKES PLACE TO ONE OF THE FLAT FACES PREVIOUSLY SANDED AND ACTING GRADUALLY ON THE FOLLOWING OF THE PROFILE TO FINISH THE END OF SANDING TANGENTIALLY TO A SECOND SIDE PERPENDED THE FIRST ONE. TO THIS EFFECT IT INCLUDES A SKATE OF HELICOIDAL SHAPE 1, THE LENGTH OF WHICH IS EQUAL TO A QUARTER OF A STEP OF THE HELICOID, THE ENTRY AND EXIT END AREAS BEING LOCATED IN ORTHOGONAL PLANS. THE ABRASIVE BAND 2 CIRCULATES ON THIS PAD CONTAINING A MATTRESS IN GRAPHITE MATERIAL 6, THE FRICTION BEING FURTHER LIMITED BY THE PRESENCE OF CYLINDRICAL INPUT AND OUTPUT ROLLERS 7 AND 8. THE INVENTION APPLIES TO THE SANDING OF ALL CONVEX ROUNDINGS OF A QUARTER OF A CIRCLE EXECUTED ON ALL MATERIALS, AND MORE PARTICULARLY IN THE FIELD OF FURNITURE, CHAISERIE OR ANY OTHER DELICATE WORK.

Description

The present invention relates to machines for executing the

  sanding convex rounded corners, particularly in

  the field of furniture manufacturing.

  Some pieces of furniture, such as chairs, for example, require the execution of a sanding operation on several tens of linear meters, components comprising, obtained at the router, roundings of radius greater or smaller. The machines hitherto used are generally of two types: continuous belt machines and disc machines. The first named use abrasive belts

  the sanding is done by a pad corresponding to the counter

  shape of the round to be sanded and acting directly on the abrasive belt; in some cases, this pad is perforated and milled, this for the purpose of diffusing compressed air at constant pressure, so as to constitute a kind of air cushion between the strip and the pad allowing a floating band

  and continuous cooling thereof. Pulleys

  deforming allow on the other hand, the adhesion of the strip to the pad. These machines have the following disadvantages need to have a range of pads corresponding to

  rounded to be sanded; use of the tape on a single part

  its width, resulting in faster localized fouling and wear of the latter. The disc machines use as a tool an abrasive disk or grinding wheel whose active face corresponds to the counterprofile of the round to be sanded. These disks may consist of a base disk on which are mounted a flexible profiled ring and an outer flexible support, the abrasive element itself conforming to the shape of the profiled ring. Other grinding discs are obtained from a polyurethane binder in which are incorporated abrasives type corundum or carbide of silicum; they may also be constituted by a system of non-woven nylon threads in which the abrasive grains are distributed and fixed by synthetic resins. The use of machines of this kind requires the user to have as many tools as rounding types to be sanded. Some machines use disks or buffers

  specialties whose shaping takes place at the moment of their use.

  according to the molding of the part b sanding. All these solutions

  Due to the diversity of the tools and the dead time involved in setting up and replacing the tools on the machine, all the disadvantages are the following depending on the abrasive tool used, whether it is a tape or a tape. shaped grinding wheel, frontal attack the rounded on the whole of its profile, causing the rapid fouling of the tool and the burning of the wood by the difficulty of clearing chips; moreover, the rotary sanding obtained with the help of the form wheels does not allow

  to achieve the quality of the sanding length.

  The machine, according to the invention, makes it possible to achieve using a single tool sanding rounded convex round quarter, regardless of their radius using in all its

  a standardized abrasive belt, without the risk of fouling

  of it, or burning the sanded material, sanding

  made by the said machine being of the enveloping type

  the sanding belt being performed tangentially to one of the previously sanded flat faces taken as reference face and acting progressively on the continuation of the quarter-round profile as b measurement of the advance of the part-b

  to sand on the machine, to reach the end of the ponçagetangentiel-

  to a second plane face previously sanded perpendicular to the first reference face, the part of the piece to be sanded to cover the entire length of the pad to obtain the total sanding of the round, the sanding station itself can be integrated into the set

  of a multiple forming machine.

  The machine, object of the invention, is mainly characterized

  characterized in that it comprises a helical-shaped pad on the surface of which circulates an abrasive continuous strip driven by a pulley-motor assembly, the active zone of the strip moving in the dihedron formed by a horizontal working table and the vertical face of a longitudinal guide, which pad is firstly adjustable in position regardless of the radius of the rounded b sanding, according to the two reference planes constituted by the table and the guide and secondly adjustable for s' adjust the value of the rounding to be sanded. The active face of the pad is a portion of helicoid limited in length

  quarter of the step so that the theoretical edges of the

  mity of the pad are in orthogonal planes, the twist angle of the abrasive belt remaining compatible with its mechanical characteristics; this active face of the pad is covered with a kind of thin mattress made of graphite material improving the friction conditions of the

  back of the abrasive belt during its passage on the skate.

  This friction is also attenuated by the presence at each end of the pad> of cylindrical ball rollers avoiding heating and wear of the strip in contact with the edges limiting the pad in its length. To ensure proper chip clearance, the band attacks the piece of wood to be sanded not frontally but at an angle; for this purpose the machining of the shoe is made so that the axis of the

  strip and the axis of the pad form a certain angle.

  The accompanying drawings illustrate, by way of example, a

  embodiment of the machine according to the present invention.

These represent:

  in FIG. 1, an overview of a multiple machine comprising

  the sanding device, - in FIG. 2, a perspective view showing the detail of the shoe and the trajectory of the abrasive belt on this shoe, - in FIGS. 3 and 4, the elevation and end views of the theoretical profile of the shoe. skid, - in Figures 5, 6, 7 and 8, different views of the theoretical helicoid constituting the active face of the pad during the pivoting thereof about the axis XX ', - in Figures 9.and 10 longitudinal views of the pad showing the end machining of the pad and the trajectory of the axis of the abrasive strip relative to the longitudinal axis of the pad, - in FIGS. 11 to 16, the various shapes of roundings being treated with the sanding device, - in FIG. 17, a perspective view of the adjusting means

and adjustment of the pad.

  The sanding device, the main characterizing element of the machine, consists of a shoe 1 whose active face of helical shape serves as a sliding path for a continuous abrasive belt 2 driven in translation along a substantially triangular path at the top of which is located the pad, the other angles respectively comprising a return pulley 3 and a drive driving pulley 4 wedged on the shaft of an electric motor 5, the tension of the strands of the band being ensured by the rocking assembly of said engine on the frame of the machine. The active face of the pad is similar to a helical portion, the surface generated by the displacement of the diameter of a cylinder resting on the axis of the latter and on a propeller drawn on the periphery of the cylinder, the helicoide similar to a screw to a thread of axis coincident with that of said helicoid, of depth equal to the radius of width equal to the diameter of the generating cylinder. The length of this helicoid portion is limited to the value of a quarter of a

  the end edges are arranged perpendicularly

  stretching relative to each other; for an observer placed, as shown in Figure 3, in alignment with the axis 00 'of the helicoid, the output edge AA' of the pad forms a right angle with the input edge BB '. The pivoting of the skate around

  the axis XX 'perpendicular to the generatrix of the helicoid

  by the point WJ situated in the middle of 00 ', makes appear for the same observer, a rounding of connection between AA' and BB ', whose radius increases with the said pivoting. The figures

  5 to 8 show the many possibilities for obtaining

  tell of all the rays that allows the machine since the simple

  blurring of the ridge to the roundness of large size.

  In the example shown in FIG. 1, the shoe 1 is connected to the frame of the machine by means of means making it possible to adjust the abrasive face of the strip b at the inlet and at the outlet of the pad with respect to the planes. reference corresponding respectively to the horizontal plane of the table of the machine and the vertical plane containing the longitudinal guide of the workpiece and through means for adjusting the value of the rounded to fit that of the piece to be sanded. To improve the sliding of said abrasive belt on the pad, the helical face thereof is lined with a kind of mattress consisting of a strip 6 of graphite soft material. This mattress is an easily interchangeable wear part. The risks of wear and heating of the abrasive belt on the edges of entry and exit of the skate

  are also attenuated by the presence of cylindrical rollers

  7 and 8 mounted on ball bearings, the said rollers

  slightly lower than the upper face

  Of the graphitized strip. In order to avoid a frontal attack of the part to be sanded by the abrasive belt, in order to obtain a good clearance of the chips, avoiding any risk of fouling

  the belt is machined in such a way that the general

  the helicoid is no longer strictly perpendicular to the longitudinal axis of the pad but forms with it an angle equal to 900 -â €, â being the angle formed by the axis of the strip and

the axis of the pad (Figures 9 and 10).

  The adjustment of the abrasive face of the strip at the level of the inlet roller 7 with respect to the horizontal reference plane constituted by the table of the machine is effected by acting on a screw 9 of control in vertical translation of the front part. skate support; the adjustment of the said abrasive face of the strip at the level of the exit roller 8 with respect to the plane of

  vertical reference constituted by the longitudinal guide is

  is killed by acting on a horizontal control screw 10 of the rear part of the pad support. These two possibilities of adjustment of the abrasive belt with respect to these two reference planes allow a perfect tangential connection of the sanding of the rounding with the preliminary sanding of

flat faces adjoining.

  The adjustment of the value of the radius of the rounding is obtained

  by a combined action on a control screw 11 in transla-

  horizontally of the front portion of the pad support at the level of the input roller 7 and on a screw 12 for vertical translation control of the rear portion of the pad support at the exit roller 8. A cutout 13 executed at the both in the table and in the longitudinal guide allows the passage of the abrasive belt 2 in the angle of the dihedron formed by

these two parts of the machine.

  According to this set of provisions, the machine performs a sanding-type sanding assimilant sanding in long quality manually performed, the attack of the piece by the abrasive strip tangentially acting on one of the flat faces, the one that is seated on the table of the machine for example, previously sanded taken as reference face, which abrasive belt acts gradually on the continuation of the quarter-round profile as and progress of the piece to be sanded on the machine to end, for example, at the end of sanding, tangentially b a second reference face

24806-62

  -6- also previously sanded, perpendicular to the first reference face, the one that is supported on the guide

longitudinal for example.

  The action on the two screws 1i and 12 allows the sanding of all types of roundings of convex shapes such as represented in a non-limiting manner in Figures 11 to 16, since the simple blurring of the edge (Figure 11) up to the rounding of a semicircle tangentially connecting the two opposite planar faces of the piece of wood (Fig. 16). Figure 12 illustrates the case of the rounding of a quarter circle connecting tangentially two orthogonal faces; Figure 13 shows a radius of rounding substantially equal to the thickness of the wooden piece tangent to one of the faces leading to the opposite face thereof by a second round of very small radius; FIG. 14 illustrates the case where a rounding tangential to one of the faces of the piece ends secant on the adjacent face, finally according to FIG. 15, it can be proceeded with the sanding of a rounding that does not result tangentially on the two flat faces adjoining. In the case of Figure 16, the sanding of the semicircle is obtained by two successive passes with reversal of the workpiece; it is the same in the case of Figure 13. The rounding, whatever the case, corresponds

always at a quarter circle.

  FIG. 17 shows the details of the fastenings of the support plate 14 of the shoe 1, on which plate are also fixed the cylindrical rollers 7 and 8. On the screw 11 used to adjust as a function of the value of the round to be sanded is mounted a handle 11 forming a nut whose screwing on the screw

  grows next to a nut 15 compressing an antago-

  16 interposed between said nut and the plate 17 fixing the screw on the frame, which spring ensures the inversion of the translation of the nut when unscrewing the handle 11a. This nut is traversed by the adjusting screw 9 of the roller 7 relative to the table, which screw is extended in the upper part by a smooth portion 9a housed in an oblong groove 18 executed in the longitudinal axis of the support plate 14 ; a compression spring 19 is interposed between the underside of the nut and a control handle 9b integral with the screw 9, the purpose of this spring being to prevent loosening of the screw under the effect of the possible vibrationq of -7- the machine by the contact pressures thus exerted on the threads of the screw, the vertical action line of the screw 9 is

  located substantially vertically above the axis of the cylindrical roller 7.

  Similarly, on the screw 10 serving to adjust the roller relative to the longitudinal guide of the machine, is mounted a handle 10a forming a nut whose screwing on the screw pushes

  following a nut 20 by compressing a counter-spring 21

  terposé between said nut and the plate 22 fixing the screw on the frame, said spring ensuring the inversion of the translation of the nut when unscrewing the handle 10a. The nut 20 is traversed by the adjusting screw 12 as a function of the value of the round to be sanded: this screw is the extension of the axis of the roll 8 whose smooth portion 12a passes through the nut, the threaded portion being limited to the lower part to receive a handle 12b forming a nut whose screwing ensures the translation

  vertical direction of the nut by pushing it, following f "in

  By these different modes of attachment of the pad, the operation of the screws 11 and 12 to achieve the adjustment of the rounding can be carried out while maintaining respectively the rollers 7 and 8 in a horizontal plane and a

vertical plane.

  The sanding unit according to the invention can be integrated as a terminal station in the assembly of a multiple machine performing the various phases of machining prior to the sanding operation roundings. Such a machine may also include in line two or more sanding units

  intervening successively on the lower and upper edges

  of the workpiece, so as to achieve for a single passage of the workpiece on the machine, the entire sanding of its straight edges, which sanding units intervene

  on one and / or the other or the other edges of the said part.

  The quality of the sanding obtained with the aid of the device involves a constant speed of movement of the workpiece s o the need for support of it by a driving device. Similarly, it is recommended to get this result,

  simultaneity of the operations of grinding and sanding.

  In the example described, the adjustment of the positioning of the

  pad is made with respect to the horizontal reference surfaces

  horizontal and vertical that constitute respectively the worktable and the longitudinal guide. According to a known technique the -8 -

  pad position 'can be determined by means of

  probes using two orthogonal faces as reference

  the pieces to be sanded, the pad being then mounted

floating head.

  The invention is not limited to the embodiment of its various parts specially indicated, but it embraces on the contrary all possible variants provided that they are not in contradiction with the object of

  each of the claims appended to this description.

  The machine equipped with the sanding device, object of the invention, can be used for all sanding operations of roundings executed on solid wood parts, chipboard, plastic or other materials, and more particularly in the field of furniture , chérie,

  worked wood or any other delicate work.

Claims (10)

- CLAIMS -   1.- Machine for sanding rounded convex round quarter regardless of their radius, using a single continuous abrasive belt standard width without risk of fouling it or burning of the sanded material, characterized in that it comprises a pad placed on the circuit traversed by the abrasive belt and on the surface of which said skid strip passes from a horizontal plane to   a vertical plane, attacking the rounded b tangential-   one of the flat faces of the previously sanded part taken as the reference face and by acting progressively on the quarter-round profile as the workpiece is progressing on the machine, in order to end in end of sanding tangentially to a second planar face of previously sanded reference, perpendicular to the first reference face, the part of the part to be sanded to traverse the entire length of the pad to obtain the total sanding of the rounding, the positioning which shoe is adjustable relative to the two reference surfaces and adjustable according to the value of the rounding b sanding.   2. Machine according to claim 1, characterized in that the active face of the pad on which the abrasive belt is circulated is a helical portion of limited lengthwise quarter of the pitch so that its end edges of entry and output are in orthogonal planes, one horizontal, the other vertical.   3. Machine according to claims 1 and 2, characterized   in that the active face of the pad is machined in such a way that the   generator of the helicoid is not strictly perpendicular   to the longitudinal axis of the pad but forms with it an angle equal to 900-Å, where θ is the angle formed by the axis of the strip.   and the axis of the shoe, this angular offset ensuring a good clearance   chip management avoiding rapid clogging of the abrasive belt.   4.- Machine according to claims 1, 2 and 3, taken   together, characterized in that the active face of the pad is lined with a mat consisting of a strip of graphite soft material promoting the sliding of the abrasive belt on the pad, which mattress forming a wear part is easily interchangeable .   5. Machine according to claims 1, 2, 3 and 4, taken   together, characterized in that parallel to the cutting edges   trea and output of the active face of the pad and tangentially to it are arranged cylindrical rollers slightly recessed with respect to the upper face of the strip   graphited in order to limit the risk of wear and heat   the abrasive belt on the said entrance edges and of the skate.   6. Machine according to claim 1, characterized in that the adjustment of the abrasive face of the strip at the inlet roller relative to the horizontal reference plane constituted by the table of the machine is carried by vertical translation of the front part of the pad support, the adjustment of the said abrasive face of the strip at the level of the output roller relative to the vertical reference plane formed by the longitudinal guide being effected by horizontal translation of the rear part of the pad , these adjustments of the abrasive belt   compared to these two reference planes allowing a connection   perfect tangential deformation of the sanding of the rounded with-the pon-   pre-treatment of adjoining flat faces, irrespective of the radius of the rounded.   7. Machine according to claim 1, characterized in that the positioning adjustment of the abrasive face of the strip according to the value of the radius of the round to be sanded is obtained by horizontal translation of the front portion of the support of shoe at the input roller and vertically translating the rear portion of the shoe support at the roller Release.   8. Machine according to claims 6 and 7 taken together   characterized in that the skate support consists of a -   plate on which are fixed the pad and the input and output rollers, which plate comprises executed in its longitudinal axis an oblong buttonhole in which engages the plumb with the input roller, the upper end of a control screw in vertical translation of the front part of the support, screwing itself into a nut by compressing a counter-spring ensuring a stability of the vertical adjustment of the input roller with respect to the horizontal reference plane, -1 1 -   which nut is movable in horizontal translation on a control screw whose end is journalled in a plate fixed on the frame of the machine, which screw associated with a compression spring allows the adjustment of the positioning of the abrasive face of the strip according to the value of the radius of the round to be sanded, which adjustment is obtained in conjunction with a second vertical translational control screw constituted by the extension of the axis of the output roller associated with a compression spring and screwing in a mobile nut in horizontal translation on a control screw whose end is journalled in a plate fixed on the frame of the machine, which screw allows the adjustment of the output roller relative to the vertical reference plane.   9. Machine according to claim 1, characterized in that the pad is mounted on a floating head, the adjustment of the pad being effected using feeler devices taking for   reference two orthogonal faces of the part to be sanded.   10.- Multiple forming machine in which integrates   terminal station, at least one ar-   according to claim 1, these units intervening   on the lower and upper edges of the   sand in order to achieve for a single passage of it over-   the machine, the whole sanding-of its rectilinear edges.