FR2759010A1 - MANUAL BELT SANDER - Google Patents

Abstract

A manual belt sander with a housing in which there is a transmission (15) which consists in particular of a ring gear (215) and a pinion (115) with an output shaft (91) mounted in at least a rolling bearing (95) can more easily be manufactured, put into service and maintained in that the output shaft (91) can be supported by being axially adjustable in the housing its axial position determining at will the play of the transmission .

Description

STATE OF THE ART The invention relates to a manual sander with

  tape with a housing in which there is a transmission-

  sion which consists in particular of a ring gear and a pinion with an output shaft mounted in at least one

rolling bearing.

  Document US-A-4,694,616 discloses a

  small manual belt sander with a drive roller

  and two deflection rollers which have a diameter which more or less coincides. These rollers pass the sanding strip over a sole which is arranged on the device in an elastic and interchangeable manner. With this hand-held device, small surfaces with different profiles can be treated well, the angles to be treated and the hollow moldings not being easily accessible due to

  relatively large diameters of the drive rollers

  and return of the manual belt sander and

  because of tangential passages that are not aligned

  between the rollers and the sole of the sander.

  We also know from the document DE-OS

  42 26 708 a fixed belt sander, the belt of which

  sanding passes on at least four rollers, and which does not have a sanding sole. This machine is intended for sanding work in which work pieces have to be worked only directly on the surface of the sanding belt on the roll-up area of the rollers,

  especially for the production of concave surfaces.

  DE-OS 39 19 651 also discloses a manual belt sander which, in addition to the conventional deflection and drive rollers,

  about the same size a small deflection roller addi-

  tional, which passes the tangential sanding strip-

  in alignment between the idler roller and the sanding sole. With this device the angles and the hollow moldings are clearly better accessible than with the other hand belt sanders. However, as its construction is based on the classic principle of hand belt sanders, the centering of the belt and the tension of the belt are carried out at an expensive cost due to the small additional deflection roller. In the case of electric tools of this type with plastic housings, one cannot do without adjusting the play of the transmission more or less

  individual due to inevitable manufacturing tolerances

  bles occurring for example by shrinking of the box

tier during cooling.

  Up to now, the play of the transmission has been adjusted on the belt by interposing adjustment washers adapted to a load or a determined number on both sides of the fixed bearing in the output line. The introduction of the adjustment washers requires a lot of skill and also involves the risk of damaging for example the sealing rings of the bearing or of not placing

  the adjustment washers correctly.

  Advantages of the invention The hand belt sander according to the invention is characterized in that the output shaft can take

  support being axially adjustable in the housing, its position

  axial position determining at will the play of the transmission

if we.

  The hand belt sander according to the invention thus has the advantage of offering significantly better handling, of simplifying the manual adjustment of the centering of the belt and

  to simplify the manufacturing and assembly as regards

  identifies the number of spare parts.

  Another advantage is that a fixed base plate carries the belt tensioning mechanism and the sanding shoe as well as other parts in the manner of a spine, being able to be mounted before mounting in the housing. In addition, the base plate which serves as a bearing cap fulfills other roles, such as collecting the roller bearing of the output shaft which

  carries the pick roller and the collection and posi-

  start up disc. The bearing cap is in the case of operation of all kinds, a

  simple stamping piece. As its assembly takes place, in-

  be without additional parts between the guide shoe and the shells of the housing, only very little is needed

  spare parts and the assembly is simplified.

  Another advantage results from the fact that the re-

  adjusting the play of the transmission during manufacture is considerably simplified, since it can be carried out from the outside on the device after its complete assembly and without additional parts, for example without washers

adjustment.

  In order to adjust the play of the transmission

  as a result, a profuse mandrel

  the. By turning this profiled mandrel with a special key

  ciale or if necessary with a screwdriver, you can adjust the play of the transmission by stop steps (The adjustment should not be made by the user, under penalty of problems). For this, the profiled mandrel is part of an adjustment disc which is located between the fixed bearing of

  the output shaft and the outer wall of the housing.

  The face of the adjusting disc which faces the wall of the housing is produced in the form of an annular key which bears on a surface integrated in the wall of the housing, which also has the form of an annular key. By rotating the adjusting disc, this gives an axial movement of the fixed bearing of the output shaft which is supported on it. For snapping into specific rotation positions the adjustment plate has a radial nose, in the form of

  spring which engages in radial grooves of

  click into the longest housing or shell. To avoid misalignment of the transmission play in the case where high axial forces are exerted on the output shaft the annular key is designed so

  self-locking. The radiating disc is passed radially

  gliding with a screw head without additional mounting directly in the housing. The material adjustment disc

  plastic in turn constitutes the seat of the fixed bearing.

  The opposing force which is necessary to maintain the play of the transmission, and which presses the output shaft and in this way the bearing permanently fixed against the adjusting disc, is exerted by an additional grease pad. In addition to its proper function

  which is to delimit a grease bowl around the bro-

  disc, its bottom has a shape such that it can axia-

  slightly flex and spring out like a disc spring.

  During assembly, this lubrication bowl is pre-stressed by the transmission cover and in this way the

  pressing force required on the fixed bearing.

  Adjustment is carried out by means of an annular key in conjunction with a lubrication bowl designed in the form of a disc spring> which at the same time forms the

  seat of the fixed bearing of the output shaft. It is possible

  ble by means of a spring-loaded snap-in nose and

  appropriate quetages in the housing to have an adjustment of the play of the transmission which clicks on it in a graduated way. The chosen setting maintains itself due to the snaps and due to a self-locking design

  of the annular key. An essential advantage of the invention

  tion lies in the simple and safe adjustment of the play of the transmission from the outside, the low number of parts and

  the fact that you don't need adjustment washers.

  In this way the sanding pad, the cover

  transmission key, housing and means for

  dre the belt have inventive characteristics, the sanding pad and the transmission cover being important components or spare parts, on which one can have sanding bands filled with

  differently or similar parts.

  According to other characteristics of the invention

  tion: * the hand belt sander has a lance-shaped outline by mounting the parts which carry the sanding band beforehand, passing them over a rear zone of the elongated housing so that they form in the zone front of the housing a wedge point protruding freely, facing forward in the center, * the hand belt sander has another sanding sole, * the idler roller has a diameter of 8 mm, * the there are between the adjustment disc and the shell latching means, which block the rotational position of the adjustment disc, Drawings The present invention will be described below

  in more detail from an embodiment, shown

  shown in the accompanying drawings, in which: - Figure 1 shows a representation in space of an embodiment of the hand belt sander according to the invention, - Figure 2 shows an exploded representation of the sander belt hand, limited to the casing and transmission, - Figure 3 shows a longitudinal section of the anterior zone of the hand belt sander, - Figure 4 shows a partial section of the adjustment plate, - Figures 5 and 6 show a top view

  and a side view of the adjustment plate.

  Description of the exemplary embodiment

  The hand belt sander 10 shown in

  Figure 1 has its sanding strip which has a thin shape, res-

  resembling a lance, with work surfaces of its wedge-shaped sanding strip at the front, ending in a nearly pointed manner, its housing 12 extending lengthwise in a straight line towards the rear , for

  receive the transmission 15 and the engine 14, which have been re-

  presented for information only. (figure 3). The bowl-

  elongated tier, in the form of a stick 12 consists of a fairly long shell and a shorter shell 112, 212,

  which are joined along a central junction line 312.

  In the rear area the housing 12 carries an on / off switch 16, which is used to start the engine for

  rotate the sanding belt 20. From the outside

  rear half of the housing 12 an electrical cable 18 comes out and in the vicinity thereof a suction nozzle 2101 of the

  dust suction channel 101, Figure 3, adjacent

  adjustment wheel 105 of an electro-

  speed selection preselection. In addition, in the rear zone and in the front zone of the housing 12 there are lateral ventilation slots 106. In the front zone, in the form of a wedge of the housing 12, the shortest shell 212 forms in relation to the longer shell. 112 a recess 412, in which a sanding strip 20 is passed in such a way that it is substantially aligned, seen laterally, on the contour of the shell la

longer 112.

  The sanding band 20 is carried by a sliding pad 33, FIG. 3 which has the shape of a wedge, with its point 333 directed towards the front. The sliding pad

  33 is provided on its wedge-shaped faces with two soles

  sanding 133, 233 and carries in front of its tip 333 on

  an articulated arm 34 with a fork 35 a pair of wheels

  return wheels 31, the pair of return rollers 31 being mounted so that they can rotate by means of an axis 32 (FIG. 3) in the fork 35. On the side opposite to the

  pair of deflection rollers we pass the belt

  çage 20 by means of a drive roller 46, FIG. 3.

  An axis of the housing 512, shown in lines and dots, marks the longitudinal extent of the hand sander to

band 10.

  In the anterior area of the shell of the box

  tier 112 the longest there is on the projecting side a

  rotary button 139, arranged in an integrated manner in a

  dark flush with the outline of the case, turn button

  nant 139 which is used to adjust the centering position of the sanding belt 20. By turning the knob 139, the articulated arm 34 which carries the fork 35 with the axle 32 and the idler rollers 31 is pivoted, depending on the

  direction of rotation in either direction.

  Completely in the vicinity of the rotary button 139, the hand belt sander 10 carries a tensioning and loosening lever 51 which also projects on the side, and which is integrated by being placed in the recess flush with the outline of the housing. , lever 51 which when pivoted down around its axis 511 releases the

  sanding tape 20 to change it.

  Can be connected to the suction nozzle 2101

  a suction pipe 103 which is used for suction of the pushers

  sanding sires by an external dust vacuum cleaner,

not shown.

  In a threaded bore 108, in the front zone of the longest shell 112 of the housing 12 can be screwed on the side an additional handle 110 by its

  threaded post 111. This way you can use the

  belt hand digger 10 in a particularly sensitive way

  sible. Figure 2 shows the hand belt sander

  10 in exploded view, and one can recognize its cons

  truction, its constituent parts and their operation, in particular the fact that the housing 12 consists of a fairly long shell and a shorter shell 112, 212 and that it forms due to the difference in length a recess 412 in the anterior zone. This is sealed by a cover of the transmission 57

  in the junction area. The area between the co-

  longest keel 112 and transmission cover

  sion forms the transmission housing, in which is located the angular gear 15 which consists of a

  toothed crown 115 and a small pinion 215. The small pi-

  gnon 215 carries, in a way that has not been shown in detail, a bearing and after which in the axial direction a ventilation wheel, to which a rotor is connected

  of the motor 14, shown in part.

  The small pinion 215 meshes with the ring gear 115 of the transmission 15 which is surrounded by a lubrication bowl 98 containing a small deposit of grease not shown and which is connected centrally to an output shaft 91 integrally in rotation. The bowl of

  lubrication 98 also partially surrounds by greasing the pe-

  tit sprocket 215 with a lateral half-nozzle.

  Above the shortest shell 212 comes the sliding shoe 33 with its tip 333, which one can clearly recognize its opening 44 and its bores 331,

  332 which turn on the side into a slot 533.

  A screw, which has not been shown at the same time, can be adjusted by means of the adjustment knob 139 and it causes the articulated lever 34 to pivot at the same time as the deflection rollers 31 to center the strip. The longest shell 112 has also been shown the adjusting disc which is used to adjust the play of the transmission between the pinions 115, 215 by axial displacement of the output shaft 91 by means of a profiled mandrel 93 of the adjustment disc 94, which passes through the housing 112 outwards to adjust the play of the transmission by means of a special tool, the internal profile being able to

  be closed by means of a stopper 193. You can see in-

  be the fixed bearing 95 which rests on the disc of

  adjustment 94. The adjustment disk 94 has a snap nose

  query 96, with which it can engage in a pro-

  snap-in thread 196, placed in the shell and can

  thus be locked in each setting position. The dis-

  that adjustment also has on its lower side more

  several segments which protrude axially with a profile

  annular key 100, which is located on an op-

  corresponding fitting of the shell 112 in the support zone

of the adjusting disc 94.

  To fix the cover of the transmission 57 in the housing 12 there are provided bores therein, in which come into engagement when mounting the punches of the housing 90. During assembly the cover of the housing 57 is inserted between the sliding pad 33 and the

  housing 12 and is fixed in connection with the punches of po-

  section 90 mentioned. It is not necessary to have

  therefore other fasteners.

  In addition to receiving the tensioning mechanism

  the cover of the housing 57 fulfills still other roles.

  A collar 86, produced during the stamping process, re-

  receives needle bearing 87 for the drive shaft

  ment 91. The sliding pad 33 is centered by means of the punch 90 in the housing 12 and is supported by means of the

  transmission cover 57 on the housing 12.

  FIG. 5 shows the anterior zone of the hand belt sander 10 in longitudinal section, on

  which we can recognize the disposition of the transmission-

  sion 15 which consists of the small pinion 215, meshing with

  the ring gear 115. Unlike the gears an-

  traditional gulars the toothed crown 115 is axially coupled at one end and not in the middle with the output shaft 91 in rotationally integral, the teeth being turned towards the output side and coming into this place in engagement with the small pinion 215. In this way, a transmission having a particular construction mode is obtained.

  flat, transmission that can be surrounded by a ma-

  simple by a lubricating bowl 98 in the form of a shell, resting on the side of the housing and which can be reliably greased in this way by means of

  of a very small deposit of fat.

  It can also be seen that the axial end side of the output shaft 91, surrounded by the fixed bearing 95, bears on an adjustment disc 94 made of plastic, which passes through the wall of the shell 112 of the housing 12 by a central axial mandrel 93 and which can be rotated from the outside with a special tool or

  also with a screwdriver or similar tool.

  The adjustment disc 94 carries on its side turned towards the housing 12 four annular keys 100, distributed regularly, projecting axially which bear on opposite annular keys 1100 carried symmetrically by the housing 12. By rotating the adjustment disc 94, for example by engaging

  a screwdriver in the profile of the mandrel 93, we make

  place it axially up and down -

  depending on the support position of the annular keys 100,

1100 on top of each other.

  A snap-on nose 96, of the spring type

  flap, projecting radially, on the outer wheel

  of the adjustment disc 94 in the form of a washer, engages in an elastic manner in a snap-on profile

  radial, integrated in the shell 112, on the seat of the device

  that of adjustment 94 or of fixed bearing 95 and is thus blocked

  only in any position by snap-on adjustment against unintentional rotation. Angles

  angular keys 100, 1100 are dimensioned so that

  ow to be self-locking so that they cannot move automatically under high axial pressure. So that the adjustment disc 94 cannot

  be moved by unauthorized persons, or another

  In an involuntary manner, it is possible to insert axially from the outside into the mandrel 93 a plug 193 which is difficult to remove. The lubrication bowl 98 serves as a disc spring, and it seeks to press the output shaft 91 in the direction

  of the fixed bearing 95 and so for relative axial forces

  constantly constant on the output shaft 91 and of this

  way it ensures a long service life to the transmission.

Claims (9)

R E V E N D I C A T IONS   1) Hand tool machine (10) with a housing (12), in which there is a transmission (15), which consists in particular of a toothed crown (215) and a pinion (115) with a shaft output (91) mounted in at least one rolling bearing (95), characterized in that the output shaft (91) can be supported by being adjustable   axially in the housing (12), its axial position deter-   undermining the play of the transmission at will.   2) Hand machine tool according to claim 1, characterized in that the hand machine tool is a hand belt sander (10) whose output shaft (91) rests in a rolling bearing (95) and takes pressing on a flat surface of an adjustment disc (94) on the wall of the housing (12), the adjustment disc (94) bearing on the side which faces the housing (12), at least one annular key ( 100)   which rests against at least one other annular key   the opposite symmetrical surface (1100) which is carried by the wall of the housing (12) and which preferably carries in the middle a   mandrel (93) which passes through the wall of the housing (12).   3) Hand tool machine according to claim 2, characterized in that the mandrel (93) is presented with axial surfaces of   coming into engagement which allow to rotate with one or   til, for example a screwdriver, the adjusting disc (94).   4) Hand tool machine according to claim 2, characterized in that the wall of the housing (12) carries a recess, which surrounds the   mandrel (93) as a sealed rotation bearing.    ) Hand-held machine tool according to claim 2 to 4, characterized in that a cap (193) can be inserted captively to close the access to the surfaces of engagement of the mandrel (93).   6) Hand tool machine (10) with a housing (12), in which there is an angular transmission (15) which consists in particular of a toothed crown (215) and a pinion (115) with a shaft output (91) mounted in at least one rolling bearing (95), characterized in that   * the ring gear (115) is connected near the ex-   end of the output shaft (91), which is mounted axially-   ment in the housing (12), in rotation with this shaft and, * the toothing of the toothed ring (115) is arranged so opposite the housing (12) and turned towards the side of the output shaft, and * in that the ring gear (115) is mounted so as to be surrounded by a lubrication bowl (98) containing a   grease deposit, closed towards the housing side.   7) Hand tool machine according to claim 6, characterized in that   the lubrication bowl (98) serves as a spring for discs and sol-   licit the output shaft (91) axially in the direction of the fixed bearing (95) by exerting a prestress on it elastic.   8) Hand tool machine according to one of claims 1 to   7, characterized in that the hand belt sander (10) has a lance-shaped outline by mounting the parts (31, 33) which carry   the sanding strip (20) beforehand, making them pass   be on a rear zone of the elongated housing (12) so that they form in the front zone of the housing (12) a wedge point (333), making freely   protrusion, facing forward in the center.   9) Hand tool machine according to claim 2 to 8, characterized in that the hand belt sander (10) has another sole sanding (233).    ) Hand-held machine tool according to claim 9, characterized in that   the deflection roller (31) has a diameter of 8 mm.   11) Hand tool machine according to claim 2 to 4, characterized in that there is between the adjusting disc (94) and the shell (112) latching means, which block the position   of rotation of the adjusting disc (94).