Planing machine for wood floors

Abstract: The planing machine for wood floors includes a truck (1) with retractable front wheels (2) and with a rear wheel (8) which is provided with means (50) for varying the attitude of the machine when the direction of motion changes; a treatment head (10) which is provided with two abrasive paper supporting rollers (11,12) which rotate in different directions, is articulately supported by the truck (1) and is provided with a portion (15a,15b) which is in contact with elastic positioning and contrast means (20-24); an aspirator (25) which conveys the wood dust into a collecting bag (28); and at least one electric motor (19) which drives the rollers (11,12) which support the abrasive paper and the aspirator.

Description: The present invention relates to a planing machine for wood floors according to the preamble of claim 1. It is known that wood floors, after laying, must be treated with planing machines which provide perfect leveling, eliminating the unevennesses which are always present in the regions of connection between one element and the other of the floor. The planing machines currently commercially available, which comprise a motorized roller which presses against the floor to be treated abrasive paper which can embrace the roller completely or can have the shape of a belt guided around an overlying pulley, have a severely disadvantageous characteristic which consists in a particularly onerous manual actuation. These machines are in fact moved backward and forward by small extents by an operator who must brake the machine when it moves in the direction induced by the rotation of the roller and must, with an even greater effort, overcome the action of the roller in order to produce motion in the opposite direction. Known from US-A-2,588,707 is a floor sanding machine comprising a frame having front and rear axles, each pivoted to the frame about an axis extending longitudinally of the direction of travel of the machine and about a point intermediate its ends, whereby each axle extends laterally on both sides of its pivot. A sanding drum is carried adjacent the end portion of each axle for rotational movement. A motor is provided for rotating the drums in opposite directions. Dust collecting means are located between the front and rear drums on each side of the frame. However, the entire frame of the floor sanding machine known from US-A-2,588,707 must be tilted to engage the floor by manually exerting more pressure on one of the rollers to move the machine across the floor to be treated. This is not only tiring for an operator, but also prejudices the uniformity of the sanding treatment which compulsorily necessitates a highly skilled operator in order to manually maintaining a uniform depth of cut of the abrasive roller as the machine is moved across the floor to be treated. Also known from US-A-3,422,579 is a planing machine as defined in the preamble of claim 1. The aim of the present invention is to provide a planing machine for wood floors which has maximum ease in manual handling for the operator, so as to spare him from any actuation effort, and can optimize its functional characteristics according to the conditions of the floors to be treated. This aim is achieved by a planing machine for wood floors as defined in the appended claims. Further characteristics and advantages will become apparent from the following description of a preferred but not exclusive embodiment of the invention, illustrated only by way of non-limitative example in the accompanying drawings, wherein: figure 1 is a perspective view of the machine; figure 2 is a partial sectional view, taken along the plane II-II of figure 1; figure 3 is a partial bottom view of the extreme left region of figure 2; figure 4 is an elevation view of the machine at the side opposite to the one shown in figure 1 and without the housing for covering the kinematic systems defined therein; figures 5 and 6 are schematic views of the different attitudes assumed by the machine in the two opposite advancement directions. With reference to the above figures, the planing machine comprises a truck 1, which is frontally provided with the wheels 2 and 3 for resting on the floor, which can be retracted into the truck from a more protruding position, assumed during the idle movements of the machine, i.e. when it is not operating, according to a per se known mechanism which comprises an axis 4 which supports said wheels by means of arms such as 3a for the wheel 3 and is rotated by an appropriate angle in the presence of the spring 5 by means of the manual actuation of a lever device, generally indicated by the reference numeral 6, which is arranged directly below the handle 7 of the machine. In a rearward position, the truck 1 is provided with a wheel 8, which is intended to rest constantly on the floor, and said wheel is provided with means suitable for automatically varying the attitude of the machine when the direction of motion thereof changes; said means, visible in particular in figure 2 and generally indicated by the reference numeral 9, will be described hereinafter. The reference numeral 10 furthermore indicates a treatment head which, according to an important characteristic of the invention, comprises two rollers 11 and 12 for supporting abrasive paper, which are motorized with different rotation directions, as indicated by the arrows of figure 1; said head is supported by brackets 13 and 14 which extend from the truck 1 by means of two pivots 13a and 14a which are inserted in flat profiled elements 15 and 16 which are rigidly associated with the cover of said head 10: this produces an articulated support of the head 10 with respect to the truck 1, with an articulation axis which is transverse with respect to the direction of the motion of the machine. The flat profiled elements 15 and 16 extend so as to monolithically support a plane 17, on which a support 18 is pivoted at 18a; said support 18 has a threaded contrast stem 18b and supports an electric motor 19 which supplies motion, according to methods described hereinafter, to all the moving elements of the machine. A wing 15a extends monolithically from the profiled element 15 and extends into a disk 15b, which is in contact with elastic positioning and contrast means, since it is inserted between the facing ends of springs 20 and 21 which are in contact, at their other end, with disks 22 and 23 which are coupled to a threaded stem 24 which is pivoted in a downward position on the structure of the truck 1; by acting on the disks 22 and 23 it is possible to both determine the position of the treatment head 10 with respect to the truck 1 and to adjust the contrast force which said treatment head encounters when, during operation, it tends to perform rotations about the articulation constituted by the pivots 13a and 14a. An aspirator 25 is accommodated within the truck 1 and has its intake connected, by means of the flexible hose 26, to the treatment head 10, so as to convey the wood dust which forms during treatment into a tube 27 which supports the handle 7 and leads, at its end, into a collection bag 28. As previously mentioned, the electric motor 19 powers both the aspirator 25, by means of a first belt 29 which is put under tension by a belt tensioner 30, and the abrasive paper supporting rollers 11 and 12, which rotate in opposite directions, by means of a second belt 31 which acts on pulleys 32 and 33 which are respectively keyed on the shafts of the rollers 11 and 12, in the presence of transmission pulleys 34 and 35; a housing 36, which is illustrated only in figure 1, constitutes the protection of said belts. With particular reference to figures 2 and 3, the means 9, with which the wheel 8 is provided and which are suitable for automatically varying the attitude of the machine when its direction of motion changes, are now described. Said means thus comprise a support 37, which is provided with the wheel 8 which is pivoted at 38 and which rotates freely about a pivot 39 with an axis 40 which does not pass through the pivot 38 and is connected to an arm 41; said arm is pivoted, at one end, at 42, on the structure of the truck 1, and is provided, at the other end, with a fork defined by arms 43 and 44 which are connected to wings 45 and 46 of a block 47 which has a through hole for a stem 48 of a traction screw with a self-locking nut 49 and actuation knob 50, which is mated with a female thread which is included in a disk 51 which is rigidly associated with the structure of the truck 1. The automatic operation of the means 9 is based on the fact that, due to stability reasons, the support 37 rotates about the pivot 39 so as to always move the point of contact of the wheel 8 with the floor into a rearward position with respect to the axis of said pivot, as can be seen in figures 5 and 6, wherein an arrow indicates the direction of motion of the machine. When the pivot 39 is in the condition of figure 2, with the axis 40 perpendicular to the floor, the position of the support 37 on one side or on the other with respect to said pivot is obviously indifferent in terms of the attitude of the machine. If instead one wishes the attitude of the machine to vary when its direction of motion varies, for example so that the abrasive paper supporting roller which is arranged further forward in the direction of motion is lower than the subsequent one, it is sufficient to act on the knob 50 and produce a rotation of the arm 41, with the consequent inclination of the axis 40 of the pivot 39 by the extent most suitable for optimizing the functional characteristics in relation to the conditions of the floor to be treated. When the axis 40 of the pivot 39 is inclined, the situation visible in figures 5 and 6 occurs, i.e. when the machine moves to the left, as in figure 5, the roller which exerts its action more deeply in the floor is the roller 11, which is the one arranged further forward in this direction of motion, whereas when the machine moves to the right the attitude thereof is changed, and the lowest roller is the roller 12, which in this direction of motion is indeed the roller arranged further forward. From all the above description it can thus be deduced that the machine according to the invention has a particularly easy actuation, since the balance of the thrusts exerted on the machine by the two rollers of the treatment head, which rotate in opposite directions, allows the operator to move the machine in both directions with minimal effort. The machine operates in optimum conditions also from the point of view of the quality of the obtained work, particularly by virtue of the presence of the articulation between the truck and the treatment head, and also by virtue of the possibility of varying the attitude of said machine, providing a floor levelling which is fully free from scratches and undulations. In the practical embodiment of the invention, the materials employed, as well as the shapes and dimensions, may be any according to the requirements. Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the scope of each element identified by way of example by such reference signs.

Claims: Planing machine for wood floors comprising a truck (1) provided with a pair of retractable floor resting front wheels (2,3), a handle (7) extending from a rear region of said truck (1) for being gripped by an operator for moving the machine, a rear floor resting wheel (8) connected to a support (37) at a pivot (38), said support being pivotally connected to said truck (1) about an axis (40) which does not pass through said pivot (38) for varying the attitude of the machine upon changing the direction of movement thereof, a treatment head (10) articulated to said truck (1) at an articulation axis (13a, 14a) extending transverse to the direction of the motion of the machine, elastic contrast and positioning means (20-24) rigidly associated with said truck (1) and contacting a portion (15a,15b) of said treatment head (10), an aspirator (21) for conveying into a collection bag (28) wood dust produced during operation of the machine, and at least one electric motor (19) for actuating said roller (11,12) and said aspirator (25), characterized in that said treatment head comprises two motorized rollers (11, 12) for supporting abrasive paper, whereby said rollers have different directions of rotation, and in that said support (37) is provided with means (39, 43-50) for adjusting the inclination of the axis (40) with which the support (37) is pivotally connected to the truck (1). Planing machine according to claim 1, characterized in that said support (37) is connected to said truck (1) by an arm (41), said arm having one end (42) pivotally connected to said truck (1). Planing machine according to claim 2, characterized in that said means for adjusting the inclination of said axis (40) with respect to said truck (1) comprise a pivot (39) connecting said support (37) to said arm (41) for rotation about said axis (40), a fork (43,44) defined by said arm (41), a block (47) located in a space delimited by said fork (43, 44), two wings (45,46) extending from said block (47) and connected to said fork (43, 44), a traction screw engaging a female thread formed in said truck (1) and having a stem (48) accommodated in a through hole formed in said block (47), and an actuation member (50) connected to an end of said stem (48) Planing machine according to claim 1, characterized in that said elastic contrast and positioning means (20-24) comprise a threaded stem (24) pivotally connected to said truck (1), two disks (22, 23) mounted on said threaded stem (24), two mutually facing springs (20, 21) mounted on said threaded stem (24) between said two disks (22, 23), wherein a wing (15a) extends monolithically from said treatment head (10) and has a portion (15b) thereof mounted on said threaded stem (24) and interposed between said two mutually facing springs (20,21). Planing machine according claim 1, characterized in that said aspirator (25) is mounted on said truck (1) and has an intake connected to said treatment head (10) by a flexible hose (26), and a delivery end connected to a collecting bag (28) by a conveyance tube (27), said conveyance tube (27) supporting said handle (7). Planing machine according to claim 1, characterized in that said electric motor (19) is mounted on said treatment head (10) and actuates belts (29, 31) provided with tensioning means (30,34,35) said two motorized rollers (11, 12) and said aspirator (25). Planing machine according to claim 1, characterized in that said retractable floor resting front wheels (2,3) are connected to said truck (1) between said rear floor resting wheel (8) and said two motorized rollers (11, 12). Planing machine according to claim 3, characterized in that said two wings (45,46) extend from said block (47) perpendicularly to said fork (43, 44). Planing machine according to claim 6, characterized in that said electric motor (19) actuates a first belt (29) and a second belt (31), said first belt (29) being tensioned by a first belt tensioner (30) and driving said aspirator (25), said second belt (31) being entrained around a plurality of transmission pulleys (34, 35) and pulleys (32, 33) keyed to the shafts of said two rollers (11, 12). Planing machine according to claim 1, characterized in that said axis (13a, 14a) is defined by pivots (13a, 14a) inserted in profiled elements (15, 16), said profiled (15, 16) being rigidly connected to said truck (1) and monolithically supporting a planar element (17), a support member (18a) being pivotally connected to said planar element (17) and supporting said electric motor (19).

Inventors: BELLATI OLGA, DEBIASI FRANCESCO, BELLATI, OLGA, DEBIASI, FRANCESCO
Applicants: BELLATI OLGA, DEBIASI FRANCESCO, BELLATI, OLGA, DEBIASI, FRANCESCO
Application year: 1992
Main classification: B24B7
IPC codes: B24B7