Patent Application
20220288740
The present invention concerns a motorized semi-manual machine tool for treating flat horizontal surfaces. In particular, the invention relates to a machine tool that moves according to a frontal linear motion.
The field of application of this machine tool is that, if equipped with specific tools, of carrying out a treatment or process such as grinding, polishing, brushing or antiquing of said surfaces.
The machine to which the present invention refers concerns the treatment of flat horizontal surfaces typically floors, or pedestrian or walkable surfaces, for example of homes, boars, jetties and walkways, etc.
More in particular, said machine tool is particularly suitable if said surfaces have grout lines or veins, such as those found on certain wooden, stone, ceramic or similar floors, more specifically, for example, parquet, marble or covered with square tiles made of various materials, such as ceramic or the like.
Generally, in prior art semi-manual motorized machine tools used for these types of treatments and processes, for example grinding machines for floors or other flat horizontal surfaces, the tools move according to a rotary, orbital or planetary rotary motion. Therefore, these machines perform a processing action of circular type, or with a circular component, on the surface being treated.
On surfaces with grooves, such as the grout lines present between tiles or between adjacent wooden boards, this type of circular/orbital movement mainly concerns the raised parts of these surfaces.
In profiles that are not perfectly flat and continuous, it is therefore difficult to reach said grooves with the tool, whether this is a brush, a paper, cloth or mesh abrasive disc, or a nonwoven pad.
Consequently, this means that with these prior art machines a great deal of time is required to treat the grout lines requires, as numerous steps are necessary in order to treat the whole of the surface involved.
However, in this way there is the risk of removing too much material on said raised parts, changing their appearance, or in some cases, damaging them.
Moreover, treating said grooves with these machines does not provide satisfactory results, as it is not easy to pass over all the small portions that were left untreated in the previous passes.
Another limit of prior art machines is that the circular movement, or with a circular component, of the tools leaves circular or curved processing marks on the surface. In the case of surfaces that have grout lines or veins of the material aligned along a main direction, these circular processing marks have a rather unattractive appearance.
The machine tool according to the present invention solves the aforesaid problems as, due to the linear movement imparted to the working tool by the machine, said grooves and said surfaces can be treated along a direction substantially aligned with said grooves or veins. A first advantage is that of obtaining an improved treatment, while a second advantage is that of reducing the times required to process a given surface.
Moreover, this machine tool does not leave circular marks on the surface being processed, representing a further advantage, as these signs are not aesthetically pleasing.
These and other objects are achieved by a motorized semi-manual machine tool, comprising at least:
The drive plate is connected to the base in a manner sliding along a direction parallel to the direction of translation of the machine tool, i.e., parallel to the longitudinal axis of the machine.
Said transmission system is configured to impart to said drive plate, and hence to the tool, a reciprocating rectilinear movement along said longitudinal direction.
In detail, the two elements, base and drive plate, are typically mutually superimposed, with the drive plate that, in a position of use of the machine, has the lower face facing the surface to be treated. Said lower face is typically substantially flat.
Hereinafter, the terms “front”, “rear” “below”, “above”, “upper”, “lower” and “side” are defined for a machine tool in a normal position of use.
According to an advantageous aspect of the present invention, the contact area between the tool and the surface to be treated extends transversely, i.e. extends to a greater degree along a direction parallel to the transverse axis of the machine.
In practice, said contact area has an extension in width (L) greater than its longitudinal extension (P), i.e. depth.
According to a preferred variant, said contact area has a ratio (L)/(P) ranging from 1 to 6, preferably from 3.5 to 4.5. Typically, the contact area has a substantially rectangular planform.
According to a preferred variant, the contact area can coincide with the area of the lower face of the drive plate. In practice, according to this variant the one or more tools that can be connected to the drive plate have a working area extending to a greater degree in transverse direction. The lower face of the drive plate thus offers a support surface for the connection of a tool or of several tools together having substantially the same dimensions and proportions.
The base can have various forms as a function of the position of the motor or of aesthetic choices, for example substantially parallelepiped or cylindrical. Typically, the base also has a substantially rectangular planform extending to a greater degree along a transverse direction.
The base has a lower (or inner) side on which the drive plate is mounted, which, during operation of the machine tool, is movable longitudinally, i.e., as indicated previously, according to a reciprocating rectilinear movement along a direction parallel to the direction of translation of the machine tool.
In particular, the drive plate has a movement preferably ranging from 5 to 30 mm.
According to an aspect of the invention, the machine comprises linear guide means to guide the reciprocating rectilinear movement of the drive plate.
According to a preferred variant, said linear guide means comprise at least one linear guide whose track is preferably fixed to the base while the slide is integral with the drive plate. Preferably at least two linear guides are provided, arranged symmetrically with respect to the centreline of the drive plate.
According to an aspect of the invention, the motor is mounted on a mount, connected to the base, which extends toward the rear part of the machine. In practice, the motor is mounted in a position farther back with respect to the base.
The motor is positioned so that its rotation axis is substantially vertical and the motor shaft is facing downward.
According to this configuration, the transmission comprises a belt that transmits the rotary motion from a first pulley, mounted on the motor shaft, to a second pulley mounted on a second shaft pivoted in the base or in the motor mount. The rotary motion of the second pulley is converted into reciprocating rectilinear motion preferably by means of a connecting rod-crank mechanism. Alternatively, a Scotch yoke mechanism or other equivalent systems can be used.
The frequency of the reciprocating motion of the drive plate depends on the geometrical features of the transmission, i.e., of the belt transmission and of the motion conversion mechanism. From tests conducted by the applicant, an optimal range is from 400 cycles/min to 1500 cycles/min, more preferably from 500 cycles/min to 1000 cycles/min.
According to a particular embodiment, this machine is equipped with rolling means configured to move said machine tool along a rectilinear direction. The rolling means are preferably wheels, typically two in number, or ball wheels.
As a function of their positioning, said rolling means can perform various functions. For example, these means can act purely as an aid for moving the machine tool in an idle condition, for example to transport it to the place of use. According to this variant, in the condition of use, the weight of the machine is discharged completely to the drive plate, or to the tool connected thereto.
According to a preferred variant, these means can also help to move the machine during use, preferably along the aforesaid rectilinear direction. In this second variant the rolling means are in contact with the surface to be treated during operation of the machine; therefore, at least a portion of the weight of the machine is discharged to them.
Typically, the wheels are positioned behind the motor mount where they do not obstruct operation of the tool and allow the machine to operate close to, or flush with, vertical edges or walls.
According to a preferred variant, the motor is positioned with its rotation axis at a distance (dr) from the axis of the wheels equal or similar to the distance (dp) between said wheels and the centreline of the drive plate taken in longitudinal direction.
Typically, the ratio (dr)/(dp) between these distances ranges from 0.5 to 2, more preferably from 0.65 to 1.5, even more preferably from 0.8 to 1.2.
According to an aspect of the invention, the handle for controlling the machine comprises a steering rod that is connected to the motor mount preferably at the axis of said motor. This steering rod is then fixed at or close to the centre of mass of the machine tool. In general, the connection point is located at a distance from the axis of the motor, taken along the horizontal direction, of no more than 150 mm, preferably no more than 100 mm, toward the front or rear part of the machine.
This positioning ensures excellent maneuverability of the machine; in particular, acting with a minimum variation of the vertical pressure on the handle, it is possible to charge or discharge the drive plate and hence adjust the pressure that the tool exerts on the surface to be treated.
Preferably, the steering rod is rotatably connected to the motor mount, so as to be able to adjust the angle with respect to the machine with the ground, and is provided with a blocking device to block said rod in a given position during operation.
Further features and advantages of the present invention will be more apparent from the description of a preferred but not exclusive example of embodiment of a machine tool as illustrated in the accompanying figures wherein:
With reference to the accompanying figures, the reference number 1 indicates as a whole a machine tool having a base 2, a motor mount 3, a handle 4, a drive plate 5 and a motor 6.
In the example illustrated, the base 2 comprises a substantially parallelepiped shaped box element open at the bottom to accommodate the drive plate 5.
More in detail, the drive plate 5 is mounted movably on the lower or inner side of the base 2. The drive plate 5 is guided by a pair of linear guides 7, each comprising a track 7a, fixed to the base 2, and a slide 7b integral with a cross bar 8 to which the drive plate 5 is connected. Said tracks 7a are oriented along the longitudinal direction of the machine.
Preferably, said cross bar 8 is provided with removable connection means, for example snap fastening means or the like, to allow a rapid attachment and removal of the drive plate 5. The motor mount 3 extends at the back from the base 2 and, in the variant illustrated, also comprises a box element 3a, with two vertical wings 3b arranged at the respective sides of the box element 3a.
The motor 6 is mounted on the motor mount 3 in vertical position with its shaft 6a facing downward. In detail, the motor 6 is resting against the upper side of the box element 3a which has a seat, not indicated in the figure, to allow the passage of said motor shaft 6a.
The transmission system further comprises a mechanism for converting the rotary motion of the second pulley 12 into the reciprocating rectilinear motion of the drive plate 5.
Said mechanism comprises a crank journal 15 fixed on the second pulley 12, a connecting rod journal 16 fixed on the cross bar 8, and a connecting rod 17 engaged with said crank and connecting rod journals, respectively with its head and foot.
The action of the connecting rod 17 on the cross bar 8 thus causes a reciprocating to-and-from linear movement of the drive plate 5 with respect to the base 2.
The machine is equipped with two wheels 20 configured to move said machine tool 1 along a rectilinear longitudinal direction. The two wheels 20 are connected in the rear part of the motor mount 3, i.e. on the opposite side with respect to the front side of the base 2.
In a preferred variant, said wheels 20 are mounted sliding vertically with respect to the motor mount 3 so as to be able to adjust their position in height. In the example illustrated, the wheels 20 are mounted on a same support 21 provided with two guide elements 21a, sliding in seats obtained in the box element 3a of the motor mount 3 and provided with blocking means to block their position with respect to said box element.
Adjustment of the wheels 20 makes it possible to use tools with different heights (or thicknesses) to be attached to the drive plate 5, while at the same time allowing said tools always to operate in a condition substantially parallel to the surface to be treated.
The handle 4 is connected to the motor mount 3 by means of a steering rod 10. As in prior art machine tools with rotary orbital movement, this rod 18 can be tilted as required, and its position can vary more or less from vertical to horizontal with respect to the surface to be treated. Usually, this position is vertical when the machine tool is idle.
According to the invention, said steering rod 18 is hinged to the motor mount 3 so that the rotation axis Xa of the rod 18 is substantially aligned, according to a longitudinal direction, with the rotation axis Zm of the motor 6. In the variant illustrated, the steering rod 18 has the lower end, i.e., facing the machine, that separates into two diverging branches 18a respectively hinged to one wing 3a of the motor mount 3.
According to an embodiment, a water dispenser 9 is arranged close to the front side of the base 2. Typically, the dispenser 9 is in the form of an elongated tube provided with orifices or nozzles for spraying water or another suitable liquid. During processing, it is this dispenser 9 can be activated so that it sprays water onto the floor surface in front of the drive plate 5. Said dispenser can be connected to an external water source, or the machine can be equipped with a tank for said water or other liquid and with pumping means.
Preferably, the drive plate 5 has a width ranging from 350 to 550 mm and depth ranging from 90 to 300 mm, although other dimensions are naturally possible.
According to the example of embodiment shown in the figures, the drive plate 5 has dimensions of 450 mm in width and 115 mm in depth. The working tool 5 has more or less the same dimensions as the drive plate 5. The total range of travel C of the drive plate 5 is around 20 mm, i.e., around 17% of its depth.
The drive plate 5 has a lower face adapted to receive and house a working tool 30, interchangeable as a function of the processing operation to be carried out and of the type of surface to be treated. This working tool 30 can, for example, be a felt polishing disc, a brush disc, an abrasive cloth disc, an abrasive mesh disc, a nonwoven disc or the like.
The invention has been described purely for non-limiting illustrative purposes, according to some preferred embodiments. The person skilled in the art can find numerous other embodiments and variants, all falling within the scope of protection of the claims below.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102019000014037 | Aug 2019 | IT | national |
This application is the U.S. national phase of International Application No. PCT/IB2020/057348 filed Aug. 4, 2020 which designated the U.S. and claims priority to IT Patent Application No. 102019000014037 filed Aug. 5, 2019, the entire contents of each of which are hereby incorporated by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2020/057348 | 8/4/2020 | WO |
