MILLING MACHINE FOR RELIEF SURFACES

AND

CONTROLLING SYSTEM OF MILLING MACHINE FOR RELIEF SURFACES

TECHNICAL FIELD

A. Milling Machine for Relief Surfaces

The invention broadly belongs to the field of machines for milling special workpieces, i.e. milling machines for relief surfaces. The invention may also be classified in the field of duplicating devices or control of milling machines for milling special workpieces with relief surfaces.

According to the International Patent Classification (IPC edition 2006.01), the following classification symbols belong to the invention: B 23 C 3/00, B 23 C 3/10, and B 23 Q 15/00.

8. Controlling System of Milling Machine for Relief Surfaces

The invention broadly belongs to the field of machines and devices for controlling machines for milling special workpieces. The invention may also be classified in the field of duplicating devices or control of milling machines for milling special workpieces with relief surfaces. It also pertains to the automatic control or regulation of forward movement, cutting speed, or position of a tool or workpiece. It also belongs to devices for driving or controlling cutting tools on machines, i.e. means for bringing the cutting element into the working position for processing, as well as to computer control systems. According to the International Patent Classification (IPC), the following classification symbols belong to the invention: B 23 Q 15/00, G 05 B 15/00 and B 26 D 5/02.

TECHNICAL DIFFICULTIES

A. Milling Machine for Relief Surfaces

The technical difficulties to be solved by the present invention consists in the following: how to structurally solve a machine for milling relief surfaces, especially for blacksmith tools for embossing reliefs in the production of metal coins, so that it performs milling of relief surfaces by its synchronized rotation of the workpiece and movement of the tool - the engraving bit in two-axis, so that the tool engraves the relief surface from the centre of the workpiece along a spiral path towards the periphery, while the movement of the tool - the engraving bit is controlled by the movement of the roller lever on which the tool - the engraving bit is placed.

The invention also solves the problem of providing control and management of mechanical assemblies of a milling machine for relief surfaces using stepper motors.

B. Controlling System of Milling Machine for Relief Surfaces

The technical difficulties to be solved by the present invention consists in the following: how to resolve a system for controlling three mechanical assemblies of a machine for milling relief surfaces using three stepper motors and one spindle motor and using a central control unit, which ensure the movement of the tip of the tool - the engraving bit and the workpiece in three-axis.

It is also necessary to provide control so that the milling machine for relief surfaces, with its synchronized turning of the workpiece and movement of the tool - the engraving bit, performs the engraving of the relief surface from the centre of the workpiece along a spiral path towards the periphery.

BACKGROUND ART

A. Milling Machine for Relief Surfaces The background art, by definition, refers to already existing solutions from practice in the field of technology that is considered by the proposed invention. Various constructions of these machines exist and are used worldwide, which were initially called pantographs. The Frenchman, Victor Janvier patented his version of the pantograph back in 1899. Since then, this type of machine with subsequent slight modifications, has been a mandatory part of the tool rooms in mints around the world. Such a machine is essentially similar to a pantograph and in practice was called a "reducer" machine. This type of machine soon replaced artists - engravers, who carved their works directly into steel, with artists - sculptors who made relief models much larger than the actual size of the coins.

The reducer machine effectively reduced the relief from a much larger model to the real size of the coin.

Such machines - called "reducer" - worked so precisely and well for a very long time in the past that it started to be said that its only drawback is its lack of obsolescence.

However, pushing such machines out of tool shops around the world began in the last 10-15 years, with the advent of CNC micro-milling machines.

One of the main advantages of the CNC micro-milling machine compared to the reducer machine is the use of models in digital format, the so-called CAD models. Coins, however, due to a higher degree of protection against forgery, did not give up hand-made motifs on the models of artists - sculptors. While for the CNC machine it is simple enough to scan the model, and thus translate it into a digital format, for the reduction machine it was necessary to undertake several painstaking steps: first taking the impression, then electroplating or casting it, in order to finally get the positive of the model in the appropriate material to be used in a reducer.

The applicant is not aware of similar solutions of milling machines for relief surfaces that use a three-axis mechanical system with a lever as a reduction element. Out of the three axes controlled by the machine (invention), two are linear and one is rotary. There are two linear axes of the linear coordinate stand (X-axis and Z-axis) that move the freely movable end of the roller lever, and as the spindle motor is fixed to it, they control the movement of the processing tool - the engraving bit, while the rotary axis controls the position of the workpiece (C-axis). The inventor noticed other shortcomings in the solutions of milling machines for relief surfaces, from the background art point of view, which were primarily reflected in the following:

- changing the profile from left to right, which was previously more difficult to do;

- more difficult change of positive to negative relief;

- in the necessary assembly and centering of the model on the machine;

- in the necessary storage space for physical models, etc.

By changing the construction in this patent application, the applicant eliminated the shortcomings of the solutions from the background art point of view that he observed.

With his original design, the inventor made it possible to precisely move the roller lever in two axes (X-axis and Z-axis) without using a physical model on the machine.

B. Controlling System of Milling Machine for Relief Surfaces

Systems and devices for remote control with the help of control units of a wide variety of machines and devices that use computer systems to control stepper motors according to a certain sequence of turning on are known in practice.

However, despite a detailed search of patent and non-patent literature, the author of the present invention is not aware of control systems for milling machine for relief surfaces as presented here. Namely, as shown in this part of the patent application, the solution of this control system with the specified control unit was created for the invention of the machine specified under item A, but it can also be applied to other similar machines or mini milling machines.

The applicant is not aware of similar control system solutions for milling machines for relief surfaces that use a three-axis mechanical system with a lever as a reduction element. Out of three axes controlled by the machine (invention), two are linear and one is rotary. There are two linear axes of the linear coordinate stand (X and Z-axis) that move the freely movable end of the roller lever, and as the spindle motor is fixed to it, they control the movement of the processing tool - the engraving bit, while the rotary axis controls the position of the workpiece (C-axis). With his invention, i.e. with an original design, the inventor made it possible to precisely move the roller lever in two-axis using the control system shown in this patent application.

DISCLOSURE OF INVENTION A. Milling Machine for Relief Surfaces

The technical difficulties were successfully solved by this patent application, i.e. construction of a milling machines for relief surfaces with the use of a tool - an engraving bit, whose path of movement is defined by the movement of a roller lever on the support of which a tool - an engraving bit is attached.

The tool - the engraving bit and the workpiece are controlled by a central control unit that sets the mode of operation of three stepper motors and one spindle motor depending on the configuration of the relief surface being processed.

The control unit that sets the operation mode of stepper motors is shown in this application under the item B - Controlling System of Milling Machine for Relief Surfaces.

The milling machine for relief surfaces consists of a supporting structure with three mechanical assemblies, namely: a roller lever assembly, a linear coordinate stand assembly and a workpiece position control assembly.

The essence of the invention consists in the construction of the roller lever assembly with its roller lever support and the spindle motor holder, at the end of which there is a tool - an engraving bit.

Therefore, the machine that is the subject of the invention consists of a support stand and movable mechanical assemblies driven by stepper motors via a control unit. In the detailed description of the invention, the structural solution of the mechanical assemblies will be described, from which the advantages of the solution in relation to the background art can be seen, while the controlling unit that manages the operation of the machine is given under the item B.

The milling machine for relief surfaces facilitates the conversion of the movement of the tool - the engraving bit to the workpiece when creating a relief from a CAD model. In relation to the solutions shown in the background art, the proposed solution of the milling machines for relief surfaces provides an essential novelty in construction: The machine that is the subject of the invention is a three-axis mechanical system with a roller lever as an element for reducing the CAD model.

The single-arm reduction lever has a backlash-free bearing at one end made with two pairs of conical-sliding or spherical-sliding bearings that allow the lever arm to move in vertical and horizontal directions. These bearings are arranged so that the vertical and horizontal axis of rotation of the lever intersect at one point.

The horizontal axis of rotation of the lever lies in the plane in which the axis of the tool takes its initial position.

In the initial processing position, this point lies on the line that connects the tip of the tool - the engraving bit and the line of support of the roller lever on the roller support (Figure 2). This line lying on these three points should be in the initial horizontal position and normal to the X-axis and Z-axis.

The freely movable end of the roller lever is in the initial position of processing in a horizontal position and rests with its weight on a roller support that is attached to the support plate of the linear coordinate stand assembly.

The linear coordinate stand carries out the movement of the roller support in the vertical direction (X-axis) and horizontal direction (Z-axis), and thus the movement of the roller lever that is supported on it. Out of the three axes controlled by the machine via the control unit, two are linear, and one is rotary (angular).

There are two linear axes of the coordinate stand (X-axis and Z-axis) that move the freely movable end of the roller lever, and as the spindle motor is fixed to it, they control the movement of the processing tool - the engraving bit, while the rotary axis controls the position of the workpiece (C-axis).

In the initial position of processing, the axis of rotation of the spindle motor (tool) and the axis of rotation of the workpiece must be on the same line, i.e. the start of processing requires coaxiality of the workpiece and the tool. The essence of the milling machine for relief surfaces is that it performs the engraving of the relief surface from the center of the workpiece along a spiral path towards the periphery with its synchronized rotation of the workpiece and movement of the tool - the engraving bit.

B. Controlling System of Milling Machine for Relief Surfaces

The invention relates to controlling system of milling machine for relief surfaces. The basic patent for the design of the milling machine for relief surfaces is given under item A.

The machine control system provides control so that the milling machine for relief surfaces with its synchronized rotation of the workpiece and movement of the tool - the engraving bit, performs the engraving of the relief surface on the workpiece from the centre of the workpiece along a spiral track towards the periphery, while at the same time reducing the CAD model, which is the essence of this invention.

The system is primarily intended for controlling a milling machine for relief surfaces with three stepper motors for controlling the mechanical assemblies of the machine and one spindle motor for moving the tool - the engraving bit, but it can be used (utilised) in the general case for controlling any processing machine that has at least three independent stepper motors and at least one spindle motor to move the tool.

The controlling system of milling machine for relief surfaces, according to the present invention, consists of a central control unit that sets the mode of operation of three stepper motors depending on the configuration of the relief surface being processed, i.e. depending on the CAD model stored in the processor. The central control unit, that is, the processing unit can be made in the form of a classic PC where the CAD model is stored.

So, the essence of the controlling system of milling machine for relief surfaces is that it performs the engraving of the relief surface from the centre of the workpiece along a spiral track towards the periphery by its synchronized rotation of the workpiece and movement of the tool - the engraving bit.

The novelty of the invention is reflected in the indirect control of the position of the spindle motor, i.e. the control is carried out with the simultaneous transformation of the movement from the linear X-axis of the machine to the circular motion of the spindle motor. Namely, the roller support on which the freely movable end of the roller lever rests during operation descends in a rectilinear line down the X-axis of the program, rotating the roller lever, and with it the spindle motor, i.e. the tool. (Figure 14)

BRIEF DESCRIPTION OF DRAWINGS

A. Milling Machine for Relief Surfaces

In order to facilitate the understanding of the invention and to show how it can be carried out in practice, the invention of the milling machine for relief surfaces is explained in detail in the drawing, as follows:

Figure 1 - View of the machine from the front, in axonometry; Figure 2 - View of the machine in the initial position, from the side; Figure 3 - View of the machine in the lower (working) position, from the side; Figure 4 - View of the machine, from the front; Figure 5 - View of the machine, from the rear right side; Figure 6 - View of the machine, from the rear left side; Figure 7 - View of the machine from above; Figure 8 - Detail A of the machine in Figure 4, in axonometry; Figure 9 - Detail B of the machine in Figure 1, in axonometry; Figure 10 - View C machine in Figure 1, in axonometry; and Figure 11 - Section A-A from Figure 2.

B. Controlling System of Milling Machine for Relief Surfaces

For easier understanding of the invention, as well as for showing how it can be carried out in practice, the applicant refers to the attached drawings where:

Figure 12 - Shows a block diagram of the controlling system of milling machine for relief surfaces;

Figure 13 - Shows a diagram of elements with connections and power supply of the controlling system; Figure 14 - Shows the arrangement of the stepper motors and the spindle motor on the machine, in axonometry;

Figure 15 - Shows the schematic position of the axes of the roller lever; and

Figure 16 - Shows the schematic position of the roller lever in the initial and lowered positions.

BEST MODE FOR CARRYING OUT OF THE INVENTION

A. Milling Machine for Relief Surfaces

The milling machine for relief surfaces according to this invention and the attached figures of the plan consists of a supporting structure composed of rectangular steel profiles, where vertical columns (1.1 and 1.3) are welded to the ends of two parallel longitudinal supports (1) from the front, and two vertical columns (1.2) are welded from the rear ends. A transverse column (1.8) is welded to the vertical columns (1.2), while the front vertical columns (1.1 and 1.3) are firmly connected by a transverse support (1.4) which is welded to them. Vertical columns (1.1 and 1.2) are firmly connected by longitudinal supports (1 and 1.5). Longitudinal supports (1) are fixed by transverse supports (1.6 and 1.7).

Three mechanical assemblies are mounted on the supporting structure of the machine, which ensure the movement of the tip of the tool - the engraving bit and the workpiece in three-axis using stepper motors.

The first mechanical assembly - the roller lever assembly, ensures that in the initial position the vertical and horizontal axis of rotation of the roller lever intersect at one point. In the initial processing position, this point lies on the line connecting the top of the processing tool and the line of support of the roller lever on the roller support. This line lying on these three points should be in the initial horizontal position and perpendicular to the X-axis and Z- axis (Figure 1).

The second mechanical assembly - the assembly of the linear coordinate stand, ensures the movement of the roller support in the vertical direction (X-axis) and horizontal direction (Z- axis), and thus also the movement of the roller lever that rests on it.

The third mechanical assembly - the assembly for controlling the position of the workpiece, ensures the angle of rotation of the workpiece (C-axis). The roller lever assembly consists of a roller lever support (9), on one side of which a vertical roller lever support (9.2) is attached, which is rotatably connected to the roller lever horizontal supports (9.3) via the upper bearing (22) and the lower bearing (23). The roller levers horizontal supports (9.3) are connected attached with screws on both sides to the rotating supports (2), which are embedded in the casings (2.1) by the shaft (3.1) of the rotating supports, while the shafts (3.1) are fixed in the supporting plates (3), which are tightly connected with clamping screws (3.2) to the vertical columns (1.2). The support column (9.1) of the roller lever support is welded at an angle on one side to the roller lever support (9), and on the other side to the vertical support (9.2) of the roller lever.

The spindle motor (4) of the tool (5) is clamped by means of the holder (4.1) of the spindle motor on the plate (4.2) of the holder of the spindle motor which is attached with screws to the adjustable plate (4.3) of the spindle motor. The adjustable plate (4.3) of the spindle motor is attached with screws through the drilled slots to the support (9) of the roller lever, by which it can be axially adjusted, and thus regulate the degree of reduction of the CAD model.

On the other side of the roller lever support (9), the roller lever (7) is attached in two clamps 7.1 of the roller levers which rest on the overhang (7.2) and which are attached on both sides with screws (7.3) which are resting on the plates from the bottom side (7.4).

The free end of the roller lever (7) rests on the roller support (8), which is part of the assembly of the linear coordinate stand.

The assembly of the linear coordinate stand consists of a support plate (13) of a roller support (8) which is fastened in clamps (12) attached with screws to the support plate (13). On the other side of the supporting plate (13), four spacers (19.3) are attached, two of which are above and two below the horizontal threaded spindle (19.2), which is connected to the stepper motor (19) via a coupling (19.1) that passes through the support (19.4) of the horizontal threaded spindle (Figure 11).

The horizontal sliders (25) are firmly attached to the spacers (19.3) with screws, and they cover sliding guides (20.1) along which they move axially in the direction of the Z-axis moving the support plate (13) together with the roller support (8). The horizontal threaded spindle (19.2) is connected via coupling (19.1) to the stepper motor (19) which drives it. During its rotation, the horizontal threaded spindle (19.2) passes through the nut (19.5), which is firmly attached to the support plate (13), which it moves axially in the direction of the Z-axis, moving the support plate (13) together with the roller support (8).

The sliding support plate (20) over the vertical sliding supports (24) covers profile guides (17). The stepper motor (16), attached to the support (16.1) of the stepper motor which is welded to the transverse support (1.4), through the coupling (15) turns the vertical threaded spindle (18), which by its rotation moves the nut (14) in the direction of the X-axis, thus moving vertically the entire assembly of the linear coordinate stand together with the roller support (8).

The vertical threaded spindle (18) from the upper side is connected to the coupling (15) resting on the upper spindle support (15.1) which is welded to the transverse support (1.4). On the lower side, the vertical threaded spindle (18) is embedded in the bearing (10), which is attached with screws to the lower transverse support (1.7).

The limiter (11) of the roller lever is clamped to the roller support (8) with a screw and can be axially adjusted by it. Its pin (11.1) limits the movement of the roller lever (7), and a leaf spring (11.2) is placed on the pin, which fixes the roller lever (7) so that it does not move axially on the roller support (8).

The vertical threaded spindle (18) rotates the stepper motor (16), which is fixed on the support (16.1), via the coupling (15). The vertical screw threaded (18), by its rotation, moves vertically (up or down) the nut (14), which is firmly attached to the sliding support plate (20), so that the entire assembly of the linear coordinate stand together with the roller support (8) moves up or down (X-axis), and with it roller lever (7) (see Figure 3).

The sliding support plate (20) via vertical profile slides 24 moves up and down along the profile guides 17 which are firmly attached to the transverse support (1.4) of the supporting structure, and on the other side are attached to the lower transverse support (1.7).

The third mechanical assembly for controlling the position of the workpiece ensures movement of the workpiece in the direction of the angular C-axis (see Figure 9).

The stepper motor (6.2) is axially movable along the support plate (21) of the casing (6.1) of the belt drive. Timing belt (6.3) is attached to a larger belt that is on the shaft of the clamping head (6) workpiece. A workpiece clamping head (6) is placed on the shaft of the larger belt, in which the workpiece (6.5) is firmly clamped using the clamping screw (6.4), using 4 to 6 clamping screws (6.4) of the workpiece, whereby the clamping screws (6.4) are evenly placed around the circumference of the clamping head (6).

On the output shaft of the stepper motor (6.2), there is a smaller reducer belt with a much smaller diameter than on the shaft of the clamping head (6), so that a much smaller angular displacement of the angular C-axis is obtained, which is regulated by the control unit that drives the stepper motor (6.2).

The operation of the milling machine for relief surfaces is simple and follows from the previous text.

The control unit (which is also the subject of the application) controls and manages the movement of the stepper motors (16, 19 and 6.2) that drive the three mechanical assemblies of the machine.

Thereof, stepper motors (16 and 19) control the roller lever assemblies and the linear coordinate stand assembly, while stepper motor (6.2) controls the workpiece position control assembly. Out of the three axes controlled by the machine via the control unit, two are linear, and one is rotary (angular).

The two linear axes are the axes in the direction of which the elements of the coordinate stand (X-axis and Z-axis) move, which move the freely movable end of the roller lever (7), and as the spindle motor (4) is fixed to it, they control the movement of the processing tool - the engraving bit (5), while the rotary axis controls the position of the workpiece 6 (C-axis).

B. Controlling System of Milling Machine for Relief Surfaces

The invention relates to a controlling system of milling machine for relief surfaces using stepper motors on the machine and a central control unit.

The technical difficulties are successfully resolved by this patent application, i.e. with the controlling system of machine (M) for milling relief surfaces using a tool - the engraving bit (5), whose path of movement is defined by the movement of the roller lever (7), on whose support (9) is attached the support of the spindle motor (4.1) which clamps the spindle motor (SPM), at the very end of which there is a tool - the engraving bit (5). Therefore, the movement of the engraving bit (5) is controlled by the central control unit (CCU), which sets the mode of operation of the three hybrid stepper motors (SMI, SM2 and SM3) and the spindle motor (SPM), depending on the configuration and quality of the relief surface that is processed on the workpiece (6).

The controlling system consists of the machine (M) on which the mechanical assemblies are located, namely assembly A of the roller lever, assembly B of the linear coordinate stand and assembly V for controlling the position of the workpiece, and directly next to the machine (M) is the control table (CT) with central control unit (CCU) and control panel (CP).

The central control unit (CCU) consists of a computer (PC), a monitor (MO), a keyboard (KB) and a processor (PU). It is connected via a USB cable to the control panel (CP) where the controller (CO) is located.

The control of three hybrid stepper motors (SMI, SM2 and SM3) as well as one spindle motor (SPM) is carried out by control unit (CCU) whose CNC program is stored in the processor (PU), and it commands the starting order of the three mechanical assemblies as follows: assembly A of the roller lever, assembly B of the linear coordinate stand, assembly V for controlling the position of the workpiece, whose positions on the machine (M) are shown in Figure 13.

The controlling system of milling machine for relief surfaces ensures the transformation from the rectilinear X-axis to the arcing motion of the movement of the tool - the engraving bit (5) when making a relief from the CAD model on the workpiece (6).

On the command table (CT) there is a central control unit (CCU) consisting of a computer (PC), a monitor (MO), a keyboard (KB) and a processing unit (PU), and the computer (PC) is supplied with electricity via cable (C) and socket (S).

The control panel (CP) consists of a controller (CO) which is connected to the central control unit (CCU) on one side by a USB cable, and on the other side, inside the control panel (CP) it is connected to the drivers (DR1, DR2 and DR3) and the inverter (IN) which receives the power supply (PI), as well as the power supply (P2) which provides power to all the drivers. On machine (M), hybrid stepper motors (SMI, SM2 and SM3) are installed, as well as a spindle motor (SPM), where the stepper motors are connected to their respective drivers, and the spindle motor (SPM) is connected to the inverter (IN).

The controlling system of milling machine for relief surfaces is carried out by transforming the movement between the linear X-axis that controls the circular axis of the processing tool - the engraver's bit (5), which performs the given movement when making the relief according to the CAD model.

The freely movable end of the roller lever (7) in the initial processing position it is in a horizontal position and rests with its weight on the roller support (8) which is attached to the support plate (13) of the assembly B of the linear coordinate stand. (Figure 14)

Assembly B of the linear coordinate stand implements the movement of the roller support (8) in the vertical direction (X-axis) and horizontal direction (Z-axis), and thus also moves the roller lever (7) which is supported on it. Out of three axes that the machine is controlled by the central control unit (CCU), two are linear, and one is rotary (angular).

The two linear axes of the linear coordinate stand (X and Z-axis) actually move the freely movable end of the roller lever (7), which is located on the support (9) to which the spindle motor (SPM) is fixed, and they control the movement of the spindle motor (SPM), i.e. tool - the engraving bit (5) located on the axis of the spindle motor (SPM), while the position of the workpiece (6) (C-axis) is controlled by the rotary axis.

In the initial position of processing, the axis of rotation of the spindle motor (SPM) (i.e. the tool - the engraving bit 5) and the axis of rotation of the workpiece (6) must be on the same line, i.e. the beginning of processing requires the coaxiality of the workpiece (6) and the tool - the engraving bit (5).

The control elements are the central control unit (CCU) and the control panel (CP), as well as the hybrid stepper motors (SMI, SM2 and SM3) and the spindle motor (SPM), which are located on the machine (M), as well as the corresponding four-core cables for connecting them.

The purpose of the controller (CO) is to receive from the computer (PC) (CCU) via the USB cable all movement commands (values X, Z, C) as well as to correctly classify and distribute them to the drivers (DRl, DR2 and DR3). The drivers will convert the information they receive from the controller (CO) about the direction and angle of rotation of the spindle motor (SPM) into a command to the stepper motors (SMI, SM2 and SM3) which they will execute.

A computer (PC) via a processor (PU) with control software is the basis of the central control unit (CCU). This part of the machine (M) control system is used to serve the controller (CO) with instructions based on which the processing is executed, i.e. to store in itself the CNC processing program in G-code form, as well as to execute the operator's command to start or stop its execution using the keys START and STOP which are visible on the monitor (MO).

The machine (M) for milling relief surfaces performs processing by points in a spiral path from the center of the workpiece (6) towards the periphery. In order to perform the processing properly in this controlling system, in which the circular motion of the spindle motor (SPM) is controlled by the rectilinear movement of the X-axis, the specifically written CNC processing program is also required.

The relief CAD model expressed in the CNC program in polar interpolation where the positions of the points are defined by X, C and Z values is the starting point for the developing the CNC program that will control the machine (M) for milling relief surfaces.

Namely, the length of the roller lever (7) in the initial position is a constant (value b in Figure 16), which is fixed in the calculation of the basic program written in polar interpolation, and the operation instructions written in this way, i.e. the CNC program, are valid only for machines with the same length of the roller lever (7) in the initial position. For machines with the same longer or shorter roller lever (7) in the initial position, a new calculation of the position of all processing points must be performed.

As an example of the implementation of the machine control system (M), Figure 16 shows schematically the roller lever (7) in its initial position as a line segment b between the points OD. During the descent of the roller support (8) on which the roller lever (7) rests, the starting point of the support D on the lever moves along the circular segment DG. The movement of the processing tool - the engraving bit (5), which is attached to the arm of the roller lever (7) by means of the spindle motor (SPM), is reduced in proportion to this circular movement DG. As the circular section DG is a proportionally enlarged path of the processing tool, all processing points must be repositioned to this circular sector. During operation, the position of point D on the CAD model during the movement of the lever corresponds to the position of the tip of the processing tool - the engraving bit (5) slightly above the workpiece (6), or the tip of the bit slightly follows the movement of point D. (Figure 16)

For example, consider the repositioning of point E on the CAD model, which has its own X and C value in the polar program.

On the machine for milling relief surfaces, the place where point E can be processed is at point G, that is, in the intersection of two circles, one is the circular path of the processing tool, and the other is the circular path of point E on the workpiece.

So, if we cross point D with point E in the processing point G, we have created a condition to process point E on the workpiece by moving the Z-axis.

Point D, which corresponds to the position of the processing tool - the engraving bit (5), will be brought by lowering the support of the lever to point F while rotating the workpiece (6) by the angle between the arms DE and DF.

The roller support (8) on which the freely movable end of the roller lever (7) rests during operation descends rectilinear down along the X-axis of the program, rotating the roller lever (7), together with the spindle motor (SPM), i.e. tool - the engraving bit (5).

INDUSTRIAL APPLICABILITY

A. Milling Machine for Relief Surfaces

The milling machine for relief surfaces, according to the present invention, operates fully automatically, using the control unit which is shown under item B. After starting the machine and placing the roller lever in the initial position, the machine automatically starts the stepper motors which, through the central control unit, and depending on the CAD model, start processing the workpiece in the proportion determined by the position of the spindle motor on the roller lever assembly. Two linear axes of the coordinate stand (X-axis and Z-axis) that move the free end of the roller lever, and as the spindle motor is fixed to it, they control the movement of the processing tool - the engraving bit, while the rotary axis controls the position of the workpiece (C-axis).

Therefore, the milling machines for relief surfaces with its synchronized rotation of the workpiece and movement of the tool - the engraving bit, performs the engraving of the relief surface from the center of the workpiece along a spiral track towards the periphery, thus transferring the relief of the CAD model from the control unit of the machine to the workpiece.

This type of milling machines for relief surfaces, which is the subject of this patent application and whose prototype was made and tested by the inventor, will most often be used in practice when making blacksmith tools for embossing reliefs when making metal coins, medals, pendants, plaques and others.

B. Controlling System of Milling Machine for Relief Surfaces

The method of application of the invention follows in an obvious way from the previous text, i.e. for the commercial use of the said invention, no special knowledge, instructions or experience are required to successfully apply the invention. Only the knowledge in the subject area possessed by an average expert is necessary and sufficient for the successful application of the subject invention, based on the given description.

All structural and functional features of the invention were successfully verified by the inventor on the prototype of the machine and its controlling system. Also, any structural improvements or changes of the invention that would be within the scope of the mechanical assemblies shown or, on the other hand, the used electrical components of the controlling system, and which would be aimed at its functional improvement, are considered to be covered by this application. PARTS SPECIFICATIONS

MILLING MACHINE FOR RELIEF SURFACES SUPPORT MN MN MNUPPORT SUPPORTUPPORTVERSE SUPPORTOLUMNRTSPORT SHAFT OF ROTATING SUPPORTLATE EWS R FOR TOOLS (EM 4) R HOLDER (EM 4) DLE MOTOR HOLDERLATE OF SPINDLE MOTORVING BIT D OF THE WORKPIECE 6. STEPPER MOTOR (EM 3) 6.1 STEPPER MOTOR SUPPORT (EM 3) 7. PROFILE GUIDES 8. VERTICAL THREADED SPINDLE 9. STEPPER MOTOR (EM 1) 9.1 COUPLING 9.2 HORIZONTAL THREADED SPINDLE 9.3 SPACER 9.4 HORIZONTAL THREADED SPINDLE SUPPORTS 9.5 NUT 0. SLIDING SUPPORT PLATE 0.1 SLIDING GUIDES 1. SUPPORT PLATE OF THE CASEING

22. UPPER BEARING

23. LOWER BEARING

24. VERTICAL PROFILE SLIDERS

25. HORIZONTAL SLIDERS

EM 1 - STEPPER MOTOR

EM 2 - STEPPER MOTOR WITH TIMING BELT DRIVE EM 3 - STEPPER MOTOR

EM 4 - SPINDLE MOTOR CARRYING THE TOOL - ENGRAVING BIT