CZ2007439A3 - Grinding machine for grinding particularly plane, concave and convex surfaces and method of using thereof - Google Patents

Abstract

The sander for sanding particularly of the flat, concave and convex surfaces and the method of its usage is based on the fact, that the sanding tool (paper, linen or other carrier with sanding abrasive layer) is pressed onto the grinded surface by means of a flexible pressure plate able to copy the concave and convex surfaces with the possibility to set accurately the radius of this curve. The principle of the technical solution of the invention of the flexible pressure plate consists in the fact, that the pressure generated during the work onto the body, handle, or handles of the sander with mechanical drive is transferred onto this pressure plate at least at two points simultaneously or over at least one balance beam.

Description

Technical field

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a hand grinder or a grinding machine with a drive for grinding, in particular, straight, concave, concave, convex, arched, hollow, hollow, convex surfaces and a method of grinding using said tool.

BACKGROUND OF THE INVENTION

At present, either hand tools such as abrasive blocks and abrasive planes, or mechanically driven hand-held vibrating, belt or linear grinders of various shapes and sizes are currently used for manual grinding of flat surfaces. Similar tools are used for grinding concave and convex surfaces, but since these tools are mainly intended for grinding flat surfaces, the ideal grinding of the desired convex or concave curves is largely dependent on the skill of the operator.

For grinding large, flat surfaces, it is advantageous to work with tools with as large a work surface as possible, both because of higher performance and, in particular, to achieve the ideal level with such a tool. However, the disadvantages of using these tools are that the larger the work surface, the more difficult and laborious the work is due to resistances and inertia forces. Another disadvantage is that it is difficult to achieve a uniform pressure of this grinding surface on tools with a large working surface. · · · · ·

-2K surface ground. The result is a compromise where the maximum length of the working surface for hand-held grinding machines is about 50 cm and the total area is about 250 cm ² . In the case of hand-held planers without machine drive, the disadvantage of large inertia forces is eliminated and the working surface of these tools can therefore be substantially extended and enlarged. However, the other disadvantages remain and, in addition, working with such a tool is physically very demanding.

The same technology is used for manual grinding of concave or convex surfaces, with the use of machine-driven grinding machines that use tools with a partially flexible working surface optimized for the size of the concave or convex curves to be ground. Partial flexibility of the work surface is achieved by inserting flexible washers between the grinding plate and the sandpaper. The use of so-called belt sanders for grinding concave and convex surfaces is almost impossible due to its construction with a fixed pressure plate. To optimize the size of the grinder, the larger the radius, the larger the work surface and vice versa.

The use of hand sanding planes utilizes flexible tools which are at least partially capable of following the radius of curvature of the surface to be ground. However, the above disadvantages remain.

* ·

3. Summary of the Invention

The abovementioned drawbacks are eliminated by a grinding machine for grinding flat, concave and convex surfaces according to the present invention, which consists in that the abrasive tool (paper, canvas or other abrasive layer) is pressed against the ground by a flexible pressure plate capable of copying also concave and convex surfaces with the possibility of precise adjustment of the radius of this curve.

The principle of the invention of the flexible pressure plate consists in that the pressure exerted on the body, handle or handles of the driven grinding machine is transmitted to the pressure plate at at least two places simultaneously or via at least one rocker. Preferably, the thrust is distributed through the bracket to at least two or more locations of the thrust plate. The number of pressure plate pressure points is determined by the number of rocker arms and brackets through which this force is transmitted through the flexible pressure plate with an abrasive layer to the ground surface. The brackets are firmly attached to the pressure plate and are movably connected to the rocker arms by means of pins so as to allow the at least one pressure plate bracket to move relative to the rocker arm. The rocker arm is therefore provided with an opening at one end and fixed statically by a pin to the brackets. At the other end, the rocker arm is provided with a groove in which the cantilevered pin can move, allowing the pressure plate to be resilient to shape the pressure plate as required by the curvature of the ground surface. When two or more rocker arms are used, the third rocker arms and each additional rocker arm are bridged by further rocker arms, while the lower rocker arms also serve as brackets. The number of rocker arms is not limited. It depends directly on the length of the pressure plate and the size of the surface to be ground. Functions of the Third and Everybody • * «444« · · 4 · · * 444 · ·· ··

-4the other rocker arm of the pyramidal arrangement and the technical design of the attachment by means of pins are similar. The top-mounted rocker arms are equally attached to the grinding body itself. in the case of hand-held planers, directly to the handle of that plane. The thrust plate using the present invention thus urges the abrasive tool against the abraded surface over its entire length of the abrasive tool with an approximately constant thrust that is uniformly distributed over the entire portion of the abrasive surface line. The solution makes it possible to use a grinding machine with a long working surface where the pressing force applied to this tool is distributed uniformly over the entire length of the surface to be grinded and at the same time allows optimum precise shaping of the curvature of the pressing plate according to the desired grinding surface.

The required curvature of the thrust plate can be fixed by means of tie rods. These rods extend from the pins of the pressure plate brackets or even the rocker rod pins to the grinding body or handle, which for this purpose is fitted with pivot pins with a transverse hole through which the rod passes freely. This pin is provided with a locking screw in the axis for possible fixing of the position of the rod with respect to this pin. Any deflection of the thrust plate changes the distance between the axes of the bracket pins or the rocker arms relative to the axes of the pivot pins located on the grinding body or handle. If the rod is not fixed to the pivot pin, the flexibility of the pressure plate is not limited in any way. If the tie rod is fixed to the pivot pin, the flexibility of the pressure plate is eliminated and the plate remains permanently in the desired curvature. The desired curvature can be set, for example, with a stencil. This technical solution enables grinding of precisely set radiuses of surfaces.

• * * ♦

-5The flexible pressure plate's own mechanism can be completely covered by inserting a flexible bellows between the rigid cover and the pressure plate itself. This bellows is fixed to the rigid cover and is only pressed against the pressure plate by means of flat shaped springs. This technical solution of the invention does not limit the flexibility of the pressure plate. The cover protects the mechanism from mechanical damage and, moreover, an abrasive dust extraction device can advantageously be connected to the fixed cover. In this case, the pressure plate and the abrasive material are provided with suction openings.

The flexible pressure plate can be used for both hand-held planers and machine-driven grinders, either linear or belt.

SUMMARY OF THE INVENTION The use of a flexible pressure plate in a machine driven linear grinding machine is characterized in that the lower surface of the pressure plate is provided with at least one movable flexible plate which is machine-driven and moves linearly between the pressure plate and the ground surface. From below, the movable flexible plate is provided with either any known system for fixing a tool for grinding, for example, sandpaper or canvas, or directly with an abrasive material. Advantageously, a system of two movable flexible plates movable along the same axis of one flexible pressure plate can be used, but always in opposite directions to each other.

♦ * »

• · · · · · · · · a a a a a a a a a a

This technical solution of the invention makes it possible to design a grinding machine with an extremely large working surface, in which the two flexible plates with abrasive material moving against each other eliminate the vibrations and unwanted kinetic forces caused by the grinding drive. At the same time, the influence of the inertia force of the grinding tool and the reaction of the work surface resistance during grinding are reduced.

The flexible movable plate is designed so that it can only move along the longitudinal axis of the flexible pressure plate, it always has to exactly copy the pressure plate and at the same time has the least impact on the flexibility of the pressure plate. The flexible movable plate is in section formed by a C-shaped profile which partially encloses the pressure plate. At the point where the profile of the plate passes from the side to the top surface of the pressure plate, the integrity of the profile is laterally disrupted by grooves at regular intervals. These grooves eliminate the longitudinal spatial rigidity of the profile, allowing the maximum flexibility of this movable plate to be maintained and totally eliminating its influence on the properties and flexibility of the pressure plate. In addition, the encircling ensures that any deflection of the pressure plate accurately follows the deflection plate. Plastic with the best possible sliding properties is chosen as the construction material of the movable plate.

The profile designed in this way can be used both in the case of a linear grinder, when the plate is provided with at least one projection for connecting the linear drive and moves in both directions linearly along the longitudinal axis of the pressure plate, or in the form of an endless belt. · ·

- unidirectionally as in the known belt sander principle. The function of the C profile and the use of a flexible pressure plate is the same as for the linear grinder.

Advantageously, a technical solution of the system using at least two or more interconnected thrust plates and at least two or more abrasive belts is provided, wherein the belts move in opposite directions to each other. This eliminates the mutual resistance, kinetic pressures and strokes of the tool and the inertia forces generated during grinding. Advantageously, the speed of the individual abrasive belts can be varied with one another, thereby assisting the grinding machine to move on the ground plate.

In a machine linear grinder, use two movable grinding plates moving relative to each other

1) Profile of the movable abrasive plate

2) Endless sanding belt profile

3) For a belt sander use a flexible pressing surface

BRIEF DESCRIPTION OF THE DRAWINGS

The technical solution of the invention will be explained in more detail by means of the drawings in which it shows

Giant. 1 is a hand-held abrasive planer according to the invention with a flexible thrust plate, wherein the thrust is transferred from the planer handle through two rocker arms. The handle also forms a separate third rocker arm in this case.

Giant. 2 shows a constructionally similar hand abrasive planer supplemented with a cover, fixing rods and dust extraction.

Giant. 3 shows a section AA of a detailed design of the fixation rods for fixing the set radius of curvature of the flexible pressure plate; and

-8Fig. 4 shows a cross-section with a detail of the attachment of the flexible bellows,

Giant. 5 illustrates the principle of a linear grinding machine with a flexible pressure plate and one movable flexible plate and the use of this grinding machine when grinding a flat surface.

Giant. 6 and 7 illustrate the use of the same grinding machine when grinding a convex resp. concave surfaces.

Fig. 8 shows the principle of a large-area linear grinding machine with a flexible thrust plate and two counter-rotating flexible plates.

Giant. 9 shows a cross-section of a flexible pressure plate with a movable C-shaped profiled plate and its partial encirclement of the flexible pressure plate and a protrusion (carrier) for connecting a linear drive.

In FIG. 10 is a view of a flexible pressure plate with a flexible movable plate with transverse grooves. The board is equipped with one projection (carrier) for connecting the linear drive.

In FIG. Fig. 11 is a cross-sectional detail view of the C profile of the transverse grooves that eliminate the longitudinal stiffness of the profile. 12 is the principle of bending a flexible pressure plate and a movable abrasive plate

In FIG. Fig. 13 is the use of a C-profile in the form of an endless belt in a belt sander with two guide rollers. 14 is a cross-section of a guide roller

Giant. 15 shows the use of a flexible pressure plate on a belt sander when grinding a flat surface.

Giant. 16 and 17 illustrate the use of the same grinder for grinding the convex and concave surfaces.

Giant. 18 shows the principle of a large-area belt sander with two flexible pressure plates and two opposing belts.

• »» * * * *

· * Ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft

Figs. 19 and 20 show the use of an identical grinding machine for grinding convex resp. concave surfaces.

List of reference marks

- basic flexible pressure plate

- foam rubber

- Velcro

- console

- pin

- pin

- groove

- rocker arm

- pin * pin

- groove

- rocker arm

- handle

- ground surface

- cover

- flexible cuff

- mouthpiece

- through hole

- rod

- tube

- pin

- Locking screw

- flat spring

- rivet

- rectangular profile • · · * ·· ΜΗ • «· ·

-1026 - hole

- movable profiled plate

- abrasives

- flexible pressure plate

31 - transverse groove

- carrier

- groove

- flexible pressure plate

- movable sanding plate

- movable sanding plate

- endless profiled abrasive belt abrasive

- flexible pressure plate

- gearing

- groove

- pulley

XX - yoke

DETAILED DESCRIPTION OF THE INVENTION

EXAMPLE 1.

Grinding machine resp. The hand sanding plane (see Fig. 1) consists of a basic flexible pressure plate 7, which is provided with a foam rubber 2 and a Velcro 3 to attach the sanding paper from below. There are brackets 5 with pins 5 and 6 on the pressure plate. The brackets are connected in two by means of rocker arms 8 on which there is a pin hole 5 at one end and a groove 7 in which the pin 6 moves at the other end. The movement occurs in any deflection of the pressure plate 1, when the distance between the pins 5 and 6 changes. The rocker arms 8 comprise pins 9 and 10. The rocker arms 8 are bridged by the rocker arm 12 to one another.

11 which has a pin hole 9 at one end and a groove U at the other end in which the pin 10 traverses the hole in the rocker arm 8. The function of the rocker arms 9 and 12 is to distribute the pressure exerted on the gripper handles uniformly throughout a pressure plate 1 which equally presses the abrasive against the surface to be ground, even when grinding concave or convex surfaces. Ergonomically shaped handles 13 are attached to the uppermost lever 12.

EXAMPLE 2.

The hand sanding plane (see Fig. 2) is similar in design to the plane (See Fig. 1). It is also completed with a rigid plastic cover 15 with a flexible collar 16 and a sleeve 17 for connecting the abrasive dust extraction hose. The pressure plate is therefore provided with through holes 18 for sucking in abrasive dust. Furthermore, the pressure plate is supplemented with rods 19 which, by fixing with respect to the upper rocker arm, enable fixation of the curvature of the pressure plate.

Detail of the function and design of the rod 19 is shown in section AA in Fig. 3. The rod 19 is rigidly connected to a tube 20 which is rotatably threaded on the pin 5. At the same time the rod 19 freely passes through the transverse hole of the pin 21 which is located rotatably across . grinder handle 12.

In the longitudinal axis of this pin 21 there is a threaded hole for the locking screw 22. If the locking bolt 22 is loose, the rod 19 can move freely through the transverse hole of the pin 21 and does not limit the flexibility of the pressure plate 1 in any way.

When the locking screw 22 is tightened, it pushes on the rod 19 and fixes it against the pin 21 and hence the grip handle 12, while fixing the point that intersects the longitudinal axis of the rod 19 with the pressure plate 7. For the strongest and most accurate adjustment of the pressure plate to the desired radius or * · ···

-12 plane it is advantageous to fix as many points as possible. use as many handles as possible.

The detail of the attachment of the elastic collar 16 is shown in section. 4 where the flexible cuff 16 is rigidly connected to the rigid cover 15. To the flexible pressure plate 1, the flexible cuff 16 is only pressed by a shaped flat spring 23, which is rigidly connected to the flexible pressure plate 1 by rivets 24. In addition, the cuff is reinforced at the bottom a rectangular profile 25 through which the springs 23 evenly press the lower surface of the sleeve 16 against the upper surface of the pressure plate 1. The reinforcing profile is provided with openings 26 into which the ends of the shaped springs 23 snap. Since the elastic sleeve is not firmly attached to the pressure plate, the bottom surface of the pressure plate is displaced relative to the upper surface of the pressure plate at any deflection of the pressure plate, thereby not limiting the flexibility and properties of the pressure plate L ·

EXAMPLE 3.

The linear grinding machine with a flexible thrust plate (see Fig. 3) is based on a similar construction and principles as the hand sanding plane (see Fig. 1 and 2). In addition, the flexible pressure plate 29 is supplemented with a machine driven movable profiled plate 27, which is provided with an abrasive 28 from below. The plate is designed as a C-shaped profile that partially surrounds the flexible pressure plate 29. A view and a cross-section of the profiled movable abrasive plate surrounding the flexible pressure plate are shown in FIG. 9 and 10. The profile of the movable abrasive plate 27 is lightened from the top side at regular intervals by the transverse grooves 31, thereby removing the longitudinal stiffness of the profile. The detail of the strain relief is shown in Fig.11. Principle and Behavior »» ··· #

13 of the relieved profile 27 with respect to the pressure plate 29 at concave respectively. The convex deflection of this plate is shown in FIG. 12. This design of the movable abrasive plate 27 allows the movable abrasive plate 27 to continually follow the press plate 29 in any deflection of the pressure plate 29, particularly when grinding concave and convex surfaces.

Furthermore, the profile 27 is provided with a protrusion 32 for connecting a linear drive. The flexible thrust plate 29 is therefore provided with a groove 33 in which the protrusion 32 moves linearly. Due to friction, the construction material of the movable abrasive plate is plastic with very good sliding properties (Teflon, etc.)

After adding the flexible pressure plate 29 and the movable plate 27 with suction holes (similar to the holes 18 on Qbr2), this design makes it possible to cover the whole mechanism similarly to an abrasive planer (See Fig. 2) and attach the grinder to the abrasive dust extraction.

EXAMPLE 4.

The large-area linear grinding machine with flexible pressure plate 34 (see Fig. 8) is based on a similar principle to the above-mentioned grinder (see Fig. 5, 6 and 7). The main difference from the abovementioned grinder is that the flexible pressure plate 34 is not fitted with one but two movable abrasive plates 35 and 36. These plates move linearly along the axis of the pressure plate 34 so that they are always opposite to each other. This solution makes it possible to substantially eliminate the abrasion resistance of the abrasive tool, so that the forces acting on the two abrasive blades always act on each other and thereby cancel each other out. Another advantage of this solution is the possibility of significantly increasing the size of the abrasive surface. Function and principle flexible «w« »

The pressure plate 34 and the ability to form the plate according to a concave or convex surface remains intact.

EXAMPLE 5.

The flexible pressure plate principle can also be applied advantageously to a belt sander with an endless belt (see Fig. 15). Movable sanding plate resp. in this case, the profile of the movable C-shaped abrasive plate is manufactured as an endless profiled abrasive belt 37 provided with abrasive 38 which unidirectionally circulates through at least 2 pulleys of which at least one is driven. Again, the strip is pressed against the ground by a flexible pressure plate 39 allowing grinding of concave or convex surfaces. The principle of encircling the pressure plate 39 with a profiled abrasive belt 37 is similar to that of a linear grinder with a profiled abrasive plate (See FIG. 10). The profiled belt has no protrusions or grips. The belt is moved only on the basis of the adhesion between the belt and the drive roller or the toothing 40 of the roller 42, which fits into the grooves 41 of the grinding belt 37. FIG. a driving pulley 42 with the principle of guiding the abrasive profiled belt 37.

In FIG. 15, 16 and 17, the principle of using a flexible thrust plate for grinding flat, convex and concave surfaces is shown on section DD.

EXAMPLE 6.

The large-area belt sander (See Fig. 18) is based on a similar principle to that of Fig. 18. 15, 16 and 17. In this case, two flexible clamping plates XX and XX are connected to one another by a yoke XX with two endless abrasive belts XX and XX moving in opposite directions to each other. In addition, the speed of the abrasive belts is relative to each other. * 4 * * * * * »A * ·« · * · ·· ·

-15 electronically controlled so that acceleration resp. slowing one belt against another will allow the grinder to move across the surface to be ground, eliminating partial physical strain on the grinder. Otherwise, this technical solution of the invention brings the same advantages as a similar counter-directional movement of the movable plates on the grinder. FIGS. 19 and 20 show the deflection of the flexible pressure plates XX and XX when grinding the convex and concave surfaces.

Industrial applicability

The technical solution of the invention is particularly applicable to new designs of hand grinders and / or grinders with a drive for grinding large flat, concave, convex surfaces and describes various advantageous ways of improving grinding using said tool.

• * · ♦ # · • «« «

Claims (1)

Patent claims The grinding machine for grinding particularly flat, concave and convex surfaces characterized by Lim is composed of a flexible pressure plate (i), at least one rocker arm (12), a bracket (4), a pin (5) and a rod (19). * * 9 9 9 9 9 9 9 9 9 «« «« «« 9 «