WO2024105708A1

WO2024105708A1 - Rotary sanding machine

Info

Publication number: WO2024105708A1
Application number: PCT/IT2023/050246
Authority: WO
Inventors: Lucio LUPI
Original assignee: Lupi Lucio
Priority date: 2022-11-16
Filing date: 2023-11-07
Publication date: 2024-05-23

Abstract

Rotary sanding machine suitable for sanding, smoothing and polishing three-dimensional surfaces due to the presence of springs suitable for connecting common abrasive discs with said sanding machine; said springs being suitable for favouring the axial and radial movement of the abrasive discs or sponge discs suitable for treating the surfaces, favouring the passage of said machine on concave, convex and flat surfaces present on the typically machined car bodies; said rotary sanding machine comprising two motors suitable for separately managing a rotary plate and at least three mandrels.

Description

DESCRIPTION

"ROTARY SANDING MACHINE"

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Field of the art

The invention relates to an innovative rotary sanding machine, suitable for sanding, smoothing and polishing three-dimensional surfaces characterised by the presence of concavities and convexities which would be difficult to reach with normal equipment on the market; more in particular, the present invention employs a plurality of springs in order to move, both radially and axially, the abrasive discs or sponges used for polishing.

Prior art

In the current state of the art, surface sanding, smoothing and polishing is carried out by hand or by means of sandpaper, further exploiting the aid of common disc sanding machines.

However, the rotation of said machines on a single plane does not allow specialised operators to reach the most insidious points, often characterised by narrow concavities and convexities. To overcome this problem, the operators are forced to use abrasive papers and pads to manually treat the most insidious parts, causing a considerable waste of time for the industrial sectors.

In the car body sector, in the event of paint restoration only, the surfaces are subjected to the following work steps:

1. manual or mechanical sanding with common sanding machines to remove the old paint;

2. manual or mechanical smoothing with common sanding machines to

SUBSTITUTE SHEET (RULE 26) make the surfaces ready for oven coating;

3. oven coating;

4. manual sanding with sandpaper or pads or mechanical sanding with common sanding machines.

Also in other sectors such as marble, in the event of the need to sand, smooth and/or polish concave and convex surfaces, the procedure currently adopted is to proceed manually with sandpapers of suitable grit size or, where possible, with common sanding machines.

However, the common sanding machines cannot treat all types of surfaces but only those which are flat or slightly concave or convex, since they are suitable for working by means of a fixed disk and therefore with the possibility of operating on a single workbench.

Therefore, such machines, while improving the production times, do not provide valid aid to the car body operators since they cannot treat all the types of surfaces.

Based on what has just been described, the operators in the sector proceed in a mixed manner, using the common sanding machines for planar or sub- planar surfaces and using manual pads with abrasive discs for surfaces with greater concavity and convexity.

It is therefore necessary to provide, in the current state of the art, a device which can facilitate the treatment of three-dimensional irregular surfaces, maintaining low machining times while ensuring high quality standards. Not even patent MY108697, published on 30 November 1996, resolves the problems mentioned, above as it describes a machine for sanding curved surfaces suitable for accommodating the components to be treated, incorporating them inside the machinery in question. Said invention represents an obstacle to the sanding and treatment of surfaces at an industrial level, as it is bulky and certainly requires significant maintenance interventions.

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SUBSTITUTE SHEET (RULE 26) The object of our patent is therefore to reveal a rotary sanding machine with two distinct electric motors, suitable for treating those concavities and convexities, comprised in three-dimensional surfaces, which cannot be reached by the other fixed-disk machines.

Description of the invention

According to the present invention, a rotary sanding machine is created which effectively solves the aforementioned problems.

The rotary sanding machine is driven by two distinct electric motors, suitable for providing a double rotation to the adhesive abrasive discs installed for the sanding process. Said machine is further suitable for polishing irregular surfaces, by means of special installed sponges.

The use of the sanding machine object of the invention allows the advantageous installation of a plurality of springs, at each abrasive disc, suitable for facilitating the rotation and translation of said disc during the treatment of three-dimensional surfaces which would generally be treated manually, prolonging work times and lowering the workmanship quality.

At least one rigid reinforcing structure is comprised inside said sanding machine, suitable for constituting a solid base on which to install the plurality of components necessary to handle and move the rotary sanding machine object of the invention.

Two handles, installed inside said rigid structure, are suitable for facilitating the gripping of said sanding machine for an operator who must sand, smooth or polish three-dimensional surfaces characterised by concavities and convexities, decreasing the fatigue due to the machining.

SUBSTITUTE SHEET (RULE 26) At least two safety switches, arranged one for each handle, are installed above, in order to allow the switching on of said sanding machine only when the operator has a correct grasp, advantageously limiting any possible risk of injury.

Two potentiometers, a separate one for each motor, are installed in order to control the rotation speed of the rotary plate and the mandrels, ensuring the operator can work hands-free, as the RPM speeds of the motors are adjustable during the sanding work.

Below one of the two handles, by way of non-limiting example, a power feeder is installed, suitable for managing the rotation speed of the rotary plate and the three mandrels by means of the pressure exerted on said power feeder by the operator.

In an embodiment thereof, said power feeder is regulated by means of a pedal arranged at ground level, freeing the operator's hands from further controls and facilitating the adjustment of the rotation speed of the rotary plate and the three mandrels.

At least one inverter is installed above said rigid reinforcing structure, in order to reverse the rotation direction of said rotary plate and said three mandrels.

Said sanding machine further comprises a first electric motor, suitable for powering the main rotary system on which a rotary plate is mounted; said rotary plate, installed at the bottom of said rigid structure, is suitable for setting in motion, by means of its own rotation, the mandrels.

The counter-rotating mandrels are installed at the bottom of said rotary plate, and are suitable for each engaging with a spring; said mandrels are suitable for adding, to their first rotation caused by said rotary plate, a further rotation by means of a second electric motor; said second electric motor

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SUBSTITUTE SHEET (RULE 26) manages the rotation of the mandrels by means of the use of a plurality of toothed wheels specially sized to obtain the most efficient reduction ratio, allowing said mandrels to rotate at the speed which best suits the machining to be performed.

By way of non-limiting example, said two electric motors are powered by a battery, comprised inside the rigid reinforcing structure and adapted to be recharged by means of induction technology.

Alternatively, said two electric motors are powered by an external battery, connected to said sanding machine by means of a power supply cable; said external battery can power a plurality of sanding machines adapted to work on the same surface at the same time.

Springs, each installed in correspondence with a mandrel, are suitable for accommodating, at their lower extremity, backing pads provided with Velcro; said springs thus allowing the three backing pads to tilt, adhering perfectly to the three-dimensional surface treated by the sanding machine.

In an embodiment thereof, said springs are adapted to be replaced in order to vary their elastic constant, optimising the sanding, smoothing and polishing processes on three-dimensional surfaces different from each other.

By way of non-limiting example, said springs are made of composite material, in order to reduce weights, consequently improving the handling of said rotary sanding machine object of the invention.

Said backing pads are each installed at the lower extremity of each spring, and are suitable for facilitating the installation of any abrasive disc by means of a Velcro; said backing pads are suitable for further accommodating a special sponge for polishing three-dimensional surfaces which are difficult to treat.

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SUBSTITUTE SHEET (RULE 26) Finally, to vacuum the dust derived from the machining of the treated three- dimensional surfaces, at least one vacuum cleaner is used, installed inside said rigid structure.

The advantages offered by the present invention are apparent in the light of the description set forth herein and will be further clarified by the accompanying figures and the detailed description.

Description of the figures

The invention will be described below in at least one preferred embodiment by way of non-limiting example and with the aid of the accompanying figures, in which:

-FIGURE 1 shows a lower perspective view of said rotary sanding machine object of the invention.

The machine comprises a rigid reinforcing structure 10 suitable for accommodating two handles 11 , suitable for facilitating gripping, favouring the handling of said machine during the sanding and polishing steps.

A safety switch 12 is comprised on each handle 11. Said safety switches 12 must be kept pressed to allow the machine to switch on, otherwise the internally installed electric motors do not allow the rotation of the abrasive discs. Said precaution requires any operator to correctly grasp the rotary sanding machine before proceeding with the machining of the three- dimensional surfaces.

SUBSTITUTE SHEET (RULE 26) A first electric motor powers the rotation of a rotary plate 14, on which the mandrels 17 are installed. Said mandrels 17, by means of a plurality of toothed wheels 18, are suitable for performing a counter-rotation with respect to the first rotation imposed by said rotary plate 14.

Springs 16 are installed below said three mandrels 17, to which backing pads 15 are installed at the bottom.

-FIGURE 2 shows a lateral half-section, of the lower part of the rotary sanding machine object of the invention.

In particular, attention is paid to the bending of the springs 16, which allow the abrasive disc, constrained to said backing pad 15, to follow the irregular three-dimensional surface, always remaining perpendicular thereto.

Therefore said pads 15, in addition to being rotated by a second motor by means of said mandrels 17 by means of a plurality of toothed wheels 18, are suitable for adapting to the surfaces on which the sanding or polishing work is carried out, forming a tilt angle which varies according to the elastic constant of said springs 16.

Said mandrels 17 are always constrained to a rotary plate 14 which imposes a first rotation thereon.

Detailed description of the invention

The present invention will now be illustrated by way of non-limiting or binding example, using the figures which illustrate some embodiments in relation to the present inventive concept.

With reference to FIG.1 , the lower perspective view of the rotary sanding machine object of the invention is illustrated.

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SUBSTITUTE SHEET (RULE 26) The present machine, in order to perform an effective machining of the irregular three-dimensional surfaces, comprises a plurality of springs 16 adapted to follow the concavities and convexities which are generally only machined manually by the operators of the sector.

Said machine comprises a rigid reinforcing structure 10, suitable for facilitating the gripping of the entire machine for each type of movement, as well as for favouring the installation of the plurality of necessary components.

At least two handles 11 are comprised on said rigid structure 10, suitable for forcing the operator to safely grasp said machine to perform the sanding and polishing of irregular three-dimensional surfaces.

Work safety is further increased by the presence of at least two safety switches 12, each installed on each handle 11. Said switches 12 must be kept pressed during all the work steps to ensure that the sanding machine remains switched on and in operation.

In an embodiment thereof, a power feeder 13 is installed below said handles 11 and is adapted to regulate the rotation speed of a rotary plate 14 and of three mandrels 17.

Said rotary plate 14 is adapted to rotate, driven by a first electric motor, imposing a first rotation on said mandrels 17.

A spring 16 is installed on each mandrel 17; said mandrels 17 are suitable for performing a second rotation by means of a second electric motor installed inside said rotary sanding machine. Said second rotation is allowed by the use of a plurality of toothed wheels 18.

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SUBSTITUTE SHEET (RULE 26) A backing pad 15 is installed below each spring, suitable for accommodating, by using a Velcro, any abrasive disc or any dedicated sponge.

With reference to FIG.2, the lateral half-section of the rotary sanding machine in question, in particular the most frequent movement characterising said backing pads 15 when they encounter an irregular three- dimensional surface, is highlighted.

As can be seen from the figure in question, in fact, the springs 16, when they encounter concavities and convexities, are suitable for bending, adapting to the treated surface, consequently reaching each portion which previously could only be processed by hand.

The springs 16 are engaged with the mandrels 17, in turn suitable for rotating due to the use of a second electric motor installed inside said rotary sanding machine.

Lastly, it is clear that the invention described up to now can be subjected to modifications, additions or variants obvious to those skilled in the art, without departing from the scope of protection outlined by the attached claims. io

SUBSTITUTE SHEET (RULE 26)

Claims

CLAIMS Rotary sanding machine characterised in that it is suitable for sanding, smoothing and polishing three-dimensional surfaces due to the presence of a plurality of springs (16) suitable for connecting a common abrasive disc with said sanding machine; said springs (16) being suitable for axial and radial movement of the abrasive discs or sponges suitable for treating the surfaces, favouring the passage of said machine over the numerous concavities and convexities present on the three-dimensional surfaces of the typically machined car bodies; said rotary sanding machine comprising two motors suitable for separately managing a rotary plate (14) and a plurality of mandrels (17); said sanding machine comprising:

- at least a rigid structure (10) suitable for providing a solid base on which to install the plurality of components necessary to implement the rotary sanding machine subject matter of the invention;

- at least two handles (11), suitable to facilitate the grip of said rotary sanding machine for an operator who has to sand, smooth or polish three- dimensional surfaces characterised by concavity and convexity;

- at least two safety switches (12), one for each handle (11), installed at the top in order to allow the switching on of said sanding machine only when the operator has correctly grasped said machine;

- at least an inverter, installed at the top of said rigid structure (10), suitable for reversing the direction of rotation of said rotary plate (14) and of said mandrels (17);

- a first electric motor suitable for powering the main rotary system on which said rotary plate (14) is mounted;

- at least a rotary plate (14), installed at the bottom of said rigid structure (10), suitable to set in motion, by its own rotation, said mandrels (17); - a plurality of counter-rotating mandrels (17), installed at the bottom of said rotary plate (14), suitable to engage with a spring (16) each; said mandrels (17) being suitable to add, to their first rotation caused by said rotary plate (14), a further rotation by means of a second electric motor;

- a second electric motor, suitable for controlling the rotation of said mandrels (17) by means of a plurality of toothed wheels (18);

- a plurality of springs (16), each installed in correspondence with a mandrel (17), suitable to accommodate, in their lower extremity, backing pads (15) provided with Velcro; said springs (16) allowing said backing pads (15) to tilt, always remaining perpendicular to the irregular three-dimensional surface being treated;

- a plurality of backing pads (15), each installed at the lower end of said springs (16), suitable to facilitate the installation of any abrasive disc by means of a velcro; said backing pads (15) being suitable to accommodate abrasive discs and further a generic sponge for polishing three-dimensional surfaces difficult to be treated due to their irregular shapes;

- at least two potentiometers, separate one for each motor, suitable for controlling the speed of rotation of the rotary plate (14) and of the mandrels (17), guaranteeing that the operator can work with the free as the RPM speed of the motors is set before starting the sanding work;

- at least a vacuum cleaner, installed inside said rigid structure (10), suitable for sucking up the dust resulting from machining the three-dimensional surface treated. Rotary sanding machine according to preceding claim 1, characterised in that at least a power feeder (13) is installed inferiorly to one of the two handles (11), suitable for managing the rotation speed of the rotating plate (14) and the plurality of mandrels (17) by means of the pressure exerted on said power feeder (13) by the operator.

3. Rotary sanding machine, according to the preceding claim 2, characterised in that said power feeder (13) is regulated by means of a pedal placed at ground level, freeing the operator's hands from further controls and facilitating the regulation of the rotation speed of the rotating plate (14) and of the mandrels (17).

4. Rotary sanding machine, according to any one of the preceding claims, characterised in that said two electric motors are powered by means of a battery, which is included within the rigid structure (10) and is further capable of being recharged by means of induction technology.

5. Rotary sanding machine, according to any one of the preceding claims 1 to 3, characterised in that said two electric motors are powered by an external battery.

6. Rotary sanding machine, according to any one of the preceding claims, characterised in that said springs (16) are suitable to be replaced in order to adjust the elastic constant of said springs (16), optimising the sanding, smoothing and polishing processes on different three-dimensional surfaces.

7. Rotary sanding machine, according to any one of the preceding claims, characterised in that said springs (16) are made of a composite material, in order to reduce weight, thereby improving the handling of said rotary sanding machine subject matter of the invention.